John Dent engineer course notebook



John Dent engineer course notebook


Covers Merlin engines, airframes, hydraulics, instruments and electrics. Detailed handwritten notes and diagrams of Lancaster aircraft systems, some b/w photographs and printed pages cut out, wiring circuit diagrams, emergency equipment, pyrotechnics.





Ninety page notebook with handwritten and printed notes


IBCC Digital Archive


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[underlined] R.A.F. [/underlined]

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CADET DENT J. 2206473

4. S of T.T. (UT/ FE.) 52 DIRECT ENTRY


A.M.O. A565/22/6/44
F/Es Revised sylabus[sic] of training & service

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[underlined] MERLIN [/underlined] XX
Reading Particulars and Limitations
1/ 12 Cyl. V (60°) Liquid Cooled, Supercharged
2/ 2 Speed s/c "M" Gear 8.15 to 1
"S" Gear 9.49 to 1
3/ Single Spur layshaft reduction .420 to 1 (28)
Bore 5.4"
Stroke 6"
Compression Ratio 6:1
Cubic Capacity 1647 cubic inches

[underlined] RATED ALTITUDE. [/underlined]
"M" Gear. 10,000 ft.
"S" Gear. 17,500 ft.
Direction of Rotation of Prop. R.H.
OIL PRESSURE High 60 to 80 min. 45 lbs/[symbol]"
Low 6 to 8 min. 2 lbs/[symbol]"

[underlined] MAGNETOS [/underlined]
2 B.T.H. C5SE.
12/6 or Ratax N.S.E. 12/4.
Direction of Rotation looking at drive end
Port. Clockwise
Stbd. Anticlockwise.
1.5 Engine Speed.
Contact breaker gap .012" fully advanced

[underlined] TIMING [/underlined]
Fully advanced Stbd 35° B.T.D.C. Pt. 45° B.T.D.C.
Rater type Stbd 45° B.T.D.C. Pt. 50° B.T.D.C.
Fully Retarded Stbd 25° B.T.D.C. Pt. 30° B.T.D.C.
Spark plug gap .012"

[underlined] VALVE TIMING [/underlined]
Tappet clearance Inlet .010"
Exhaust .020"

[calculations inserted]

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[underlined] CARB. A.V.T. /40/193 [/underlined] S.U.
Duplex Double Entry

[underlined] FUEL. [/underlined]
100 Octane – pump pressure to 10lb [symbol]”

[underlined] COOLENT. [/underlined]
Ethylene Glycol 70/30

[underlined] STARTING [/underlined]
Hand & Electric
15:1 100:1

[underlined] PROP. [/underlined]
D.H. Hydromatic fully feathered C.S. Control
Ratal external cyl 35° pitch and range

[underlined] INTERNATIONAL RATING [/underlined]
1240 B.H.P. +9 1175 B.H.P. +9
2850 R.P.M. 2850 R.P.M.
10,000 "M" Gear 17,500 "S" Gear

Pipes 1/2" O.D. and over Double Width of Bands.

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[underlined] ARRANGEMENT OF CYLINDERS:- [/underlined]
In 2 blocks of 6 Angle between 60°
Stbd "A" Block Port "B" Block.

[underlined] FIRING ORDER:- [/underlined]
"A" 1 4 2 6 3 5 [circled] 1 2 3 4 5 6 [/circled]
"B" 6 3 5 1 4 2 [circled] 1 2 3 4 5 6 [/circled]

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[underlined] CYL. BLOCK [/underlined]
Aluminium Alloy casting. Monoblock construction

[underlined] VALVES. [/underlined]
Non-magnetic steel – tips treated with [underlined] stellite [/underlined]
Seating faces and crowns – [underlined] brightrey[?] [/underlined]
Inlets – solid
Exhaust – Sodium filled
Valve stems fitted with "C" clip.
Inlet 45°
Exhaust 44 1/2°
Valve springs made by R. R. C. V. Steel.

[underlined] VALVE GUIDES [/underlined]
Inlet – Cast Iron
Exhaust – Phospher bronze.

[underlined] VALVE SEATS [/underlined]
Silicon steel – Shrunk and screwed into block
Inlet + Exhaust 45°

[underlined] GUIDE TUBES [/underlined]
Alum bronze held by lock nuts and "C" clips

[underlined] LINERS [/underlined]
N.C. Steel nitrided – nickel plated externally.
ribbed liners C plated internally tap 2 1/4" to resist wear. Sealing at top by Alum joint rings – at bottom by rubber rings – liners retained in position when not on engine by clamps – loading on block retaining nuts – Ribbed liners 110ft lbs – plain 140ft lbs
4 end nuts 90ft lbs in each case

[underlined] CRANK SHAFT. [/underlined]

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[underlined] CYLINDER BLOCK ASSY. [/underlined] (Single Piece Block)

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[underlined] Crank Shaft. [/underlined]
1/ Nickle chrome steel forging with 7 main bearings and 6 throw in pairs 1 & 6, 2 & 5, 3 & 4 angle between 120°.
2/ Hollow, lubricated by high pressure oil from gallery pipe. Also lighters C/S.
3/ Located by No.4 main bearing.
4/ Splined coupling flange bolted to front for layshaft of reduction gear. Sp
5/ Splined coupling to rear of shafts takes tortion [sic] bar and secondary shaft
6/ C/Pins and bearings nitrided.

[underlined] CONNECTING ROD ASSY. [/underlined]
Forked and plain rod type. The fork carries a split steel bearing (lead bronze lined).
The inner liner bears on hardened C/Pins whilst outer liner forms bearing for plain and rod.
Connecting rods have plain fully floating bushs [sic].
Plain ended in "A" Block
Forked ended in "B" Block.

[underlined] UPPER HALF CRANKCASE. [/underlined]
1/ Incorporates rear half of reduction gear and bearing
2/ Universal oil seal situated in upper half bearing of reduction gear and is connected by union on top
3/ C/C breathers connected to air intake
4/ Middle stbd side is mounted relief valve unit
5/ Port towards rear is generator mounting
6/ Rear face machined for wheel case.
7/ Upper surface machined for cyl. blocks and have cyl bore holes and 14 studs holes per block.
8/ Inside are 7 C/Case webs for main bearings. Split steel shell lined with lead bronze, U.S.A. Silver-lead-indium

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9/ Stud holes for bearings
10/ Transverse bolts in side to strengthen C/Case. Cross ways (2 per web).
11/ Inside Stbd (Internal oil gallery pipe).
12/ Mounting feet for engine to frame.
13/ No. 3 & 6 aperture locates blocks No. 3 .005" all round No. 6 .005" laterally
14/ Scavenge out drains down 5 exhaust side guard tubes to sump.
15/ Wheelcase located by semicircular spigot & dowels.
16/ Reduction gear housing located by semicircular spigot and 2 hollow dowels.
17/ Carries outer races of Reduction gear
18/ Bronze dowels locate bearing caps.

[underlined] PISTONS, ASSY. [/underlined]
Alum. alloy, forging. Fully skirted concaved, 3-Compression Rings 2-Scraper, (1 above & 1 below the gudgeon pin)
6° to 8° taper to allow for expansion at top of piston. Crown drilled to minimize distrortion[sic]
Fully floating gudgeon pin retained by 2 clip. Compression rings backed off 1° to 1 1/2°
Scraper rings channel section. All rings are of cast iron with scarfed joints.
Pistons stamped:- No. wt, compression ratio. Wt stamping to left of fitter when on assy.

[underlined] CAM SHAFT. [/underlined]
1/ Made from forged steel and is hollow for oil distribution and to resist shock.
2/ No. 7 bearing locates
3/ Is carried in 7 bearings.
4/ Cams in pairs (Inner - inlet – outer - exhaust)

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5/ Rotates half engine speed
6/ Oil flinger on end of C/S to lub. gears
7/ Pt. camshaft rear end E.S.I.
8/ Stbd. Rt, Heywood compressure.
L.H. Hydraulic pump (Guns)
9/ Rocker spindle is keyed in No. 7 bearing
10/ Holes in bearing bracket for lubrication from No. 7 & through cam shaft and rocker shaft.
11/ Cam shaft keyed to beval [sic] gear.
12/ Rotation clockwise:- Exhaust cam leads.

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[underlined] REDUCTION GEAR. [/underlined]
Spur gear driven by coupling layshaft.
Range gear bolted to prop shaft.


MERLIN. British Standard Airscew [sic] Shaft. (Straight Splined).
Split centralising cone fitted to locate prop and to prevent it being out of track.
Down centre of prop. is Oil Transfer Tube.
Reduction Gear is jet lubricated.
Driven off front of R/G small pinion by quill drive shaft are aux drive units C.S.U. (Port) Vacuum pump (Stbd.)

[underlined] COOLANT PUMP [/underlined]

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30% Ethylene Glycol [underlined] D.T.D. 344 or 344A [/underlined]
70% water
Coolant is under pressure of 30 lbs/[symbol]" so that if the pressure rises, then [underlined] thermostatic relief valve [/underlined] in header tank will allow pressure to return to 30 lbs. While when engine cools a vacuum may form therefore a relief valve is fitted onto vacuum bellows. When engine is started and coolant is cold, the coolant passes through [underlined] Thermostat [/underlined] up to 85°C and bypasses the radiator, but by pass is not completely closed until 105°C. [underlined] Assists warming up & prevents too rapid cooling [/underlined]

To maintain correct working temp. of engine – the 30 lbs/[symbol]” pressure raises boiling temp. and prevents coolant boiling at lower temp when at altitude
Press 70/30 boils at 135.0°C freezes at -15°C
No Press 70/30 boils at 103.5°C freezes at -15°C

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CLARKES VISCOSITY VALVE – By passes cold oil and admits hot oil [indecipherable word]. By pass loaded 30 lbs/[symbol]" valve to cooler 16 lbs/[symbol] spring


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[underlined] Worths Oil Dilution [/underlined]
For easy starting and adequate initial lubrication of bearings. Fed into oil system before oil pressure pump (Suction side). Ease the strain on starter mechanism.
Solenoid operated valve

Stop engine and allow oil to cool 25° to 40°C.
Restart and run engine at 1000 R.P.M.
Press button
0° to -10°C 1 minute
-10° to -20°C 2 minutes
-20° below 3 minutes

Keep button pressed and at same time pull the Cut-out.
Keep it pressed till engine stops.

[underlined] VOLUTE DRAIN SYSTEM:- [/underlined]

When slow running the mixture condenses in the volute casing and endangers the impeller, therefore a drain is fitted from the volute casing to a pipe into a venturi

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in the Carb, air inlet, and to the manifold. During slow running the depression formed in the manifold draws off fuel from volute case, but when boost pressure increases there is a blowback to induction.

Priming System:-
Tri. gass [sic] pump to manifold are 5 priming points, 4 on manifold 1 on induction elbow.
In fuel connections there are fuel imulsifiers [sic]
Pipes from Pt to Stbd are connected by drilling[?]
* Stbd is union for volute
* Pt is priming.


Amal Pressure Reducing Valve:-
1/ Maintains a constant fuel pressure to Carb.
Fuel pump press. varies due to:- (felt at back of relief valve)
a) Distance of tanks
b) Varying head of fuel.
c) Altitude.
Back pressure from float needle valve moves diaphragm allowing spring tention [sic] to decrease flow of fuel past valves. Corrected for altitude by conveying air intake press to back of diaphragm, which will progressively close intake. Fitted upside down for self flushing. Double action valve a safety measure.

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Engine driven fuel pump – pressure to Amal valve flucuates [sic] about 15 lbs/[symbol] mark. (Imersion [sic] pumps off – on etc Amal valve reduces same to 6 to 8 lbs.
Fuel warning lights "on" red when pressure drops below 6 lbs [symbol]”


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To conserve power at low altitudes and take off. "M" 8.15 "S" 9.49
To increase altitude, takes 80 B.H.P. for "M" gear and 160 for "S" gear.
All gears are in CONSTANT MESH, engagement and disengagement effected by clutches.
Engagement is effected by centrifugal force acting on bob weights, disengagement by cam operated selector fork presses a thrust ball race against the bob wts. preventing them being thrown out by cent. force. The forks are interconnected as one gear is engaged the other is disengaged, cam operated by a servo, piston working on scavenge oil. Manually controled [sic] in cockpit.
Automatically controled [sic] by aneroid and electro pheumatic [sic] ram. (Fighter A/C only).

Vanes on back of blower casing for:-
1/ Increase pressure of mixture delivered from the impeller
2/ Gives direction to mixture from impeller to induction chamber
Compression ratio 2.3 to 1. 2600 R.P.M.

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SU. AVT/40/193


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[underlined] Checking Boost Enrichment Needle[/underlined]:-
9 lbs pressure in the aneroid chamber. Projection of needle .18" One turn of adjusting [sic] screw .090” movement of needle.
Tolerance .010" but not when checking. .060 wear allowed in linkage

[underlined] Altitude Mixture Control. [/underlined]:-
Zero boost = 29.92" mercury, (Hg) Rate of correction .030" for every 1" H.G. when atmospheric pressure is standard or 29.92” needle projection if correct should be 0.1" (Way of ajustment [sic] same as Boost Enrich, Needle).

[underlined] Diffuser System [/underlined]:-
A normal diffuser system fuel drain through main jet, emulsified by air from pressure balance chamber impinging on it, drawn out of top of diffuser into choke tube, mixed with air and becomes a suitable carburetted mixture – Diffuser keeps fuel and air proportionate (cruising range) [underlined] above cruising conditions all air holes are uncovered, at this point we get boost enrichment [/underlined] 2650 + 7 & above.

[underlined] Pressure Balance System [/underlined]
Ensures air pressure in air intake and sealed float chamber is balanced, this prevents any inequality of pressure between these two localities upsetting the mixture. Weak and Rich mixture control no longer fitted.
Adjustment of level of fuel in fuel chamber is made on eccentric mounting of connecting rod. (10 lbs [symbol]" pressure in chamber, level from joint face .515 – .635 held for 3 mins

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Automatic Boost – Control.
1/ This controls no boost above 10,000 ft in"M" Gear
2/ A.B.C controls any boost up to its rated altitude (taking each boost is rated boost of engine). +9 to 10,000, +4 10,000


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R.R. (ABC) Progressive Type.
As throttle lever is moved forward the unit is progressively reset to control at higher boosts, and within the limits of the unit any one position of the throttle lever will always give the same boost. Working Range of Unit +2 lbs to +9 lbs, +9 lbs obtained with throttle at gate (R.B.) The variable datum action stops at plus +2 so as [two deleted words] the boost drops below this figure the servo piston will remain fully forward and control of the butterflies will be direct by the throttle lever (Manual.)

[underlined] Atmospheric Change Over Lock[/underlined]:-
At very low boosts the pressure difference across the supercharger is so low that the Servo piston would tend to move instead of the butterflies when the throttle lever was moved therefore when boost falls below zero the change over cock substitutes atmos. pressure instead of boost to the rear of the relay piston thus holding it fully forward more positively

[underlined] Through the Gate [/underlined]:-
Throttle lever at gate, boost control is set for +9 and moving throttle through the gate does not alter this setting. At sea level with throttle lever at gate relay piston is at rear of cylinder therefore movement through the gate will result in the butterflies being open direct – the boost control still trying to reduce the boost to +9 but unable to do so as the relay piston is already fully rearward. The movement through the gate is so set that on a Normal day the boost will be +12. As this boost is uncontroled [sic] it will decrease as soon as the A/C leaves the ground.

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[underlined] Boost Control Cutout [/underlined]:-
In flight the max. permittable boost of +12 cannot be obtained with the throttle lever, As the boost control has a max. setting of +9 and going through gate in flight produces no results therefore to obtain +12 in flight the cutout [deleted one letter] must be pulled. Use of this cutout when the throttle is at gate causes pressure in aneroid chamber to drop from +9 to +6 the relay piston imediatley [sic] moves forward opening butterflies until pressure in aneroid chamber is +9 but because of the leak caused by cutout the supercharger pressure required to give +9 aneroid is +12 The boost regulator will now control this figure up to the full throttle hieght [sic] of +12

[underlined] Setting Rated Boost [/underlined]:-
Throttle lever at gate, pull datum lever cam down until mark on cam lines up with mark on rocker. Connect link work and check. Any further ajustment [sic] made at ajusting [sic] screw on rocker

[underlined] Setting T.O.B. [/underlined]
Slacken off control shaft stop screw Turn control shaft until mark T.O.B. lines up with split in bush housing. Screw in stop screw to [deleted one letter] touch stop on blower housing. Run up engine 3000 R.P.M. (T.O) throttle through gate, boost should read +12 on normal days.

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[underlined] LAYOUT OF MERLIN AUXILARY [sic] DRIVES [/underlined]


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Magneto Timing:-
Turn C/S d.o.r to "A"6M.A. (Stbd or Pt) Fully advanced Brush to A6 segment with use of lamp and battery. Turn mag. until light goes out and reset to engine drive. Test by turning C/S back (lamp on) and turn till lamp goes off again.


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[underlined] 2154 GALS FUEL [/underlined]


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Fuselage Construction:-
The fuselage is semi monocoque.
The [underlined] formers [/underlined] and [underlined] stringers [/underlined] are made of pressed alkalad sheet. The whole is covered with a [underlined] stress skin [/underlined] of alkalad sheeting
The fuselage is built in 5 seperate [sic] sections which are bolted together at formers E, 6, 12, 27 with High Tensile Stainless Steel bolts. These joints are known as transportation joints

Construction of Main Planes:-
The main planes are built around 2 Spars known as Front & Rear Spars. The Main Plane Centre Sections are built in with the fuselage Centre Section and cannot be removed individually, but the main plane can be removed from centre section. The wing tip is detachable and so is the portion of both the centre section and the main plane rear of the rear spar

The internal structure of ribs and stringers is covered with a stressed [inserted] skin [/inserted] of alkalad sheet.

Tail Unit:-
The internal structure of tail plane is 2 Spars, ribs, and stringers, these are covered with a stressed skin of alkalad sheeting. Both tail planes are seperate [sic] but are bolted together in fuselage. The fins are fully outrigged and have a leading edge of laminated wood to which the stressed skin is screwed

* Formers 1, 6, 12, 19 Pressed Steel on Fuselage

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[deleted][underlined] Starting Up [/underlined]:-
1/ Cross feed cock “off”
2/ Tank selectors, selecting No 1 tanks
3/ All 4 Master cocks “on”
4/ Warm up taxy, and “take off” with selectors No 2
5/ Both No 2 & 1 tanks pulsometer pumps must be switch on for “take off” (40 galls fuel used approx. for running up, taxi, & take off for all 4 engines) [/deleted]

[page break]

[deleted][inserted] DUFF GEN [/inserted][underlined] At 1000ft [/underlined]:-
1/ Switch “off” all 4 Pulsometer Pumps
2/ Continue running off no 2. tanks until 120 gals. have been used out of each.
3/ Switch on no 3. Pulsometer pump.
4/ When both No 3 are empty switch “off” pulsometer pump (15 to 20 min to empty 3 into 2).
5/ Continue running off both No 2. until approx. 70-100 galls. remains in each No 2 tank.
6/ Select both No 1 tanks by Selector cocks.

[underlined] Use of Pulsometer Pumps [/underlined]:-
No.1/ Take off. No 1 & 2 Switch on.
2/ Landing Both No 2 & 1
3/ Over Target Area or in Combat No 1 & 2
4/ When changing over tanks No 1 & 2.
5/ At altitudes about 15,000 ft. Turn on pulsometer pumps of the tanks being run on at that time
6/ When draining No 3 tanks into No 2. switch on both No 3 pulsometer pumps.
7/ When running all 4 engines off one tank on one side of system. Switch on pulsometer pump.

[underlined] To run all 4 engines off any one tank [/underlined]:-
1/ Open Cross Feed Cock
2/ If not already selected [deleted word] select tank on which you are to run all 4 engines
3/ Switch on pulsometer pump for that tank
4/ Turn selector cock off on opposite side to which our single tank is. [/deleted]

[underlined] Pulsometer Pump [/underlined]:-


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[page break]

Oxygen System Ground Check:-
No. 1/ Open master cock.
2/ Open contents gauge cock or Regulator and [indecipherable word] that system is 7/8 full
3/ Set altitude regulator to 35,000 ft.
4/ Remove bayonet union from clip and valve, hold it to your ear and economiser should give from 5 to 9 puffs per min. (Check all economisers)
5/ If the oxygen has any trace of mustiness it is U./S. the hold system must be emptied and refilled


[page break]


There are 4 - 3 pint methol [sic] bromide fire extinguishers. One behind each fireproof engine bulkhead.

Methods of operation:-
1/ Push buttons – 1 for each engine – Stbd of panel.
2/ Flame switch – 8 off – 2 on front of engine bulkhead. Operate at temp between 110° - 140°C
3/ Gravity Switch – operates when a/c is inverted and when u/c is locked down only. Situated in nose – Stbd. operates 4 bottles
4/ Invertion Switch – operates 4 bottles when A/C make heavy landing. Situated 2 Stbd side of B/A compartment.



Control valve situated by W/O seat Pt & Stbd. Turn C.V. anticlockwise to allow hot air into cabin, open sliding shutters in extractor louvres in B/A compartment to all hot air to be decipated [sic] around cabin and allowed to atmosphere.

Check for cabin heating:-
1/ Inboard engines running
2/ Close windows & armour plated doors
3/ Turn on control valve to heater.
4/ Open louvres.

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Fire up above
by John T. HENSHAW

FIRE, during flight or as the result of a crash, has always been one of the airman's greatest perils. Only a few years ago fire in the air usually meant abandoning one's aircraft, and the risk of fire following a crash was very great indeed.

Today the danger is greatly reduced. All heavy aircraft used by the R.A.F. are now fitted with fire-fighting equipment which, in an emergency, is operated automatically.

Most fires, of course, start in the engine compartment, and are usually due to fuel or oil flooding the hot engine. It is to be expected, therefore, that any system for reducing fire risks will pay particular attention to the engines. This is a noticeable feature of the system employed on nearly all R.A.F. machines, in which each engine is protected. Operation is effected by a series of automatic and manual switches wired into an electrical circuit.

As shown on the diagram, four types of switches are fitted in each circuit to meet all possible emergencies.

[inserted]*[/inserted] The crash or inertia switch is fitted in the forward portion of the hull or fuselage, and is, as its name suggests, operated in the event of a crash. The action is entirely automatic, and is almost instantaneous with the aircraft striking the ground.

[inserted]*[/inserted] The gravity switch is also mounted in the forward part of the fuselage,
and operates in the event of the aircraft turning over on to its back after landing. But, you may say, if turning upside down closes the switch, what happens during inverted flight or aerobatics? Well, this difficulty is overcome by connecting the switch into another electrical circuit, so that it is out of action during flight. A common way of doing this is to connect the gravity switch in circuit with the switch controlling the retractable undercarriage. Then only when the undercarriage is fully down and locked ready for landing is the gravity switch on. When the undercarriage is retracted the switch is off.

[inserted]*[/inserted] Two flame- or temperature-operated switches are fitted in each engine compartment, one near the carburettor and the other at the rear of the engine. These, as their name suggests, are actuated by contact with a flame or by a rise to about 150 degrees C. in the surrounding temperature.

The remaining switch or push-button control is for manual operation. One button is fitted for each engine, and all are mounted within easy reach of the pilot, so that they are ready at hand in any emergency.

The extinguishers themselves are mounted conveniently close to the


engines, usually on the fireproof bulkhead. One extinguisher is fitted in each engine bay on Service aircraft, and all are actuated by the previously mentioned switches. Apart from these, however, each crew station is equipped with an extinguisher, but these are always hand-operated, and do not, on Service aircraft, comprise part of the automatic fire-fighting equipment.

In all cases, though, the extinguisher consists of a metal bottle charged with methyl bromide at about 60 lb./sq. in. pressure. From the extinguisher, spray pipes are led around the engine nacelle, as shown on the illustration. All danger points such as the air intake, carburettor system or any pockets where fuel may collect are embraced by the circuit, the fire-quenching chemical being sprayed through the perforated piping or, where a concentration is required, through special nozzles.

If an engine catches fire during flight or on the ground the flame switch, operated by the flames or the rise in temperature in the engine bay, immediately energises the extinguisher. The methyl bromide is released under pressure and surges along the tubing, spraying the engine and nacelles through the nozzles and perforated piping. In this way the engine compartment is flooded with the chemical, and dense flame-quenching fumes are produced.

A further effect of the methyl bromide is to evaporate rapidly when released, thus cooling any metal with which it is in contact. In this way hot metal is cooled below the flash-point of petrol or oil, and so prevented from igniting any fuel which may drip from fractured pipes or shattered tanks.

In the event of a crash the inertia switch instantly actuates the extinguisher in each engine bay. Every engine is smothered with the chemical almost immediately the crash occurs. The hot parts are cooled before leaking fuel or oil can reach them, and the risk of fire is greatly reduced.

If the aircraft should overturn on landing all the engines are again protected. The gravity switch, as we have seen earlier, operates immediately the aircraft turns on its back, but the effect is exactly the same as that of the crash switch. The extinguisher at each engine is energised and all the engine compartments are smothered.

The above-mentioned switches are, as we have seen, operated without any action whatever on the part of the pilot. In fact, he could not operate them himself if he wanted to. It is, however, very desirable that he should have a means of control, and this is provided for by the push-button switch.

In the unlikely event of one of the automatic switches failing to act, he has an alternative control ready at hand, and in any other emergency he can smother any or all of his engines quickly and effectively.

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It can be seen that an alert captain can (a) anticipate what the attacking aircraft can do, and will attempt to do, and (b) that by adept handling of his ship he can comb an oncoming torpedo track by turning [italics] towards [/italics] it or, if he has the speed of a destroyer, outpace the torpedo by turning away.

Thus few individual attacks are successful, whilst a converging attack, well synchronised, forces the ship to decide instantaneously what action it can take to avoid the most dangerous


A Wellington's torpedo on the way down. Torpedo-carrying Wellingtons have operated against Axis shipping in the Mediterranean.

torpedo, then trying to avoid that torpedo whilst presenting a much improved target to the originally less-dangerous torpedo.

The art of gauging a ship's speed is to be learned by practice. The size of the ship, its length, the wake it is leaving and the extent of its bow wave all figure in the pointers that may qualify the pilot's estimate.

How the Ship Turns
One interesting fact is that the ship always turns directly on the line of a helix or circle, although it follows an average line. In non-nautical language, the ship altering course may be presumed to take up a succession of positions rather than steer a clean line.

The rudder is at the stern of the ship. If "right rudder" is applied as in flying, the aftermost part of the rudder moves to the right (starboard) of the ship's fore-and-aft line. Pressure of oncoming water on this surface causes the ship's stern to be pushed to the left (port). But as the pressure is only caused by the ship being under way, the stern moves left and forward – in a direction north-west if the ship is heading north. Hence the bows "turn to the right", exactly as in flying whilst the ship heels over to the left, as it cannot (as in flying) apply bank and rudder in a turn.

The track of a ship in a turn is shown diagrammatically, the size of the rudder being exaggerated for demonstration purposes.

Thus frequently the first indication a pilot has of the ship altering course as he swoops to attack is the evidence in the wake of application of rudder, this causing a violent disturbance in the sea.

It can be seen that torpedo attack is a battle of wits. The pilot requires an alert mind to figure out first the intricacies of placing himself in the best position for attack and, secondly, having made up his mind, to be ready and able to make split-second adjustments to his decision according to the behaviour of the ship attacked.

More than half a million tons of enemy shipping have fallen to Swordfish torpedos.

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[underlined] OLEO LEGS [/underlined]:- "LANCASTER" CHARGING:-

[underlined] Oil level check [/underlined]:-
1/ When wt. of A/C on wheels assume that the A/C has been undisturbed for a considerable period. This allowes [sic] the oil to find its correct level.
2/ Remove dust cap from charging valve, and connect gauge adaptor
3/ Screw in valve "A" on adaptor, open valve "B" and watch leg compress, just before it becomes fully [indecipherable word] a fine oil and air mist should be given off valve "B"

[underlined] Topping Up leg with oil [/underlined]:- Use "Inner[?]" Adaptor [/underlined]
1/ Screw out valve "A"
2/ Screw in valve "B"
3/ Connect "Vickers" 2 way pump.
4/ Pump in oil, but keep a check on the air pressure in the leg by periodically ceasing to pump and screwing down valve "A". The air pressure must never exceed [underlined] 2325 lbs/[symbol]" Pump untill [sic] legs just begin to move.
5/ Screw in valve "A" and open "B". This will allow air press to escape and blow off any surplus oil in leg
6/ Screw out valve "A" and screw in "B". Pump in

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50 lb [symbol]" air press, allow this to escape by screwing in valve "A" and open "B". This blows off any oil which may have run down from the walls of the leg.

[underlined] Air Charging [/underlined]:-
1/ Jack up A/C until wheels are clear of ground [inserted] and fully extended [/inserted]
2/ Screw out "A" and in "B"
3/ Pump in air press of [underlined] 995 [/underlined] lbs [symbol]" check extension after removing [indecipherable word]

[underlined] Tail Strut [/underlined]:-
Same as above except the air pressure when charged must be between [underlined] 600-650 lbs [/underlined][symbol]"

[underlined] Tyre Pressure [/underlined]:-
Main Wheels – 4 3 lbs [symbol]"
Tail Wheels – 54 lbs [symbol]"


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These tables are to give a check against the correct amount of oil in oleo. With the wt. of A/C on the oleo Correct amount of oil will give a range of air pressures and an extension of oleo in inches.

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Both Rudders are metal covered, each has a trimming tab and external [deleted word] balance and horn balance. They are also differentual [sic], longitudinal control about Normal Axis.

In a turn the rudder on the outboard of the turn will move through an arc of 22 3/4°. While the rudder on inboard travels through an arc of 22 1/2°



The elevators are a welded tubular construction. Fabric covered. Each elev. has a trimming tab, balance tab and an internal mass balance. The hinges are inset

AILERONS are fabric covered. Each has a balance tab. Only STBD has a trimming tab. Both have an internal mass balance.

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[underlined] ELEVATOR CONTROLS [/underlined]


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[underlined] PNEUMATICS [/underlined]:- CPL. COLE

[underlined] HEYWOOD PRESSURE REGULATOR [/underlined]


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Brakes being applied:- Inlet open Exhaust closed.

[underlined] Faults [/underlined]:- Brakes “off”
Faulty inlet valve - lost pressure from system
Brakes "on"
Faulty inlet valve – too much pressure
Faulty exhaust loss of pressure

[underlined] Adjustments [/underlined]:-
To reduce pressure screw in adjuster where cable passes into dual relay valve.
To increase – screw adjuster out.
The cable adjuster is for adjusting cable only.

[underlined] Checks [/underlined]:- before take off and also before landing.
1/ Main Pressure 150 lbs[symbol]" before take off. Max 300 lbs [symbol]"
2/ Put both brakes on and check pressure – 80 lbs [symbol]"
3/ Take rudder bar off central and test individual brakes
4/ Progressive braking

[underlined] Electro Pneumatic Jack's [/underlined] (Radiator).
Air operated both ways. When energised by thermostatic switch, piston will be retracted (Shutters open). The Thermo switch automatically operates the temp. of engine coolant.
Rises to 115°c or 105°c Closes 109°c 98°c When temp falls opposite occurs. An over ride switch is fitted on F./E Panel to allow shutters to be fully open for ground running.
Air pressure must be above min. pressure to operate this jack. 105 + or - 5lbs[symbol]”

[underlined] "M" & "S" Gear Jack [/underlined]:- Operated by switch pilots panel below engine speed indicator – One switch for 4 engines
A red warning list beside switch indicates "S" gear when on ground only. (When undercarriage is locked down) check air pressure before attemping [sic] "S" ratio.

[underlined] Rams [/underlined]: Single acting retracted by C./A extended by spring. In case of failer [sic] of elec or pneumatics rams return to "M" ratio, must go down to lower altitude 10,000 ft.

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[underlined] Idle Cut out [/underlined] MK III
4 Switchs [sic] of pilots panel just above starter buttons control individual engines. These switchs [sic] have 2 positions
Up – Engines running.
Down – Idle Cutoff [sic]

[underlined] Rams [/underlined]:- Ason [sic] "M" + "S" gear. in case of failer [sic] of elec or pneumatics rams will return to engines running.

[underlined] (a) COMPONENT (b) POSITION (c) PURPOSE [/underlined]
(a) Heywood Compressor (b) Stbd Inner "A" Bank. (c) Maintain pressure of air in system & bottle
(a) External Charging Valve. (b) Aux Panel of Stbd U/C Nucel.
(a) Oil & Water Trap. (b) Aux Panel of Stbd U/C Nucel. (c) Prevent oil & water from getting into system.
(a) Heywood Pressure Regulator. (b) Front Engine Bulkhead (c) Permit pressure to idle & reduces pressure
(a) Air Bottle (b) B/A Compartment [deleted] Port side [/deleted] In roof.
(a) Air Filter (b) Port side B/A. (c) Filter air
(a) Four Way Connection (b) Port side B/A. (c) Directs air to Dual Relay Valve T.P.I. & through min. press. valve
(a) Min. Pressure or pressure maintainance [sic] (b) (Below 4 way union 6") III B/A [indecipherable word] behind engine bulkhead I (c) To ensure suffiant [sic] press. for [indecipherable word]. Jacks 105 lbs[symbol]” + or - 5
(a) Dual Relay Valve. (b) Linked to rudder pedals (c) See Notes.
(a) T.P.I. (b) Pilots panel Stbd. Side.

Localising Faults.
1/ Bottle to D.R.V. (2nd. Inlet valve).
2/ D.R.V. and Port Brake (Brake on).
3/ D.R.V. and Stbd Brake (Brake on)
4/ Min Press. Valve to Pheum. Jacks.
[underlined] Comp. [/underlined] Pressure reducing Valve
[underlined] Position [/underlined] Between each engine bulkhead and rad shutters
[underlined] Purpose [/underlined] Reduces press to 220lbs [symbol]”

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[underlined] Power Circuit [/underlined]

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Fluids:- 1/ INTAVA No 675 Colour Red.
2/ INTAVA 695 Colour Red.
3/ 2. DTD44D 1 - Intava 694.
4/ Imergency [sic] D.T.D.44D.
Fluid needed for system 19 1/2 gals.

[underlined] RESERVOIR [/underlined]:-


[underlined] AUTOMATIC CUT OUT [/underlined].


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[underlined] Accumulator:- [/underlined] Purpose.
1/ To damp out pressure waves caused by restrictions and hammering of auto – cut out.
2/ To give immediate starting of all services.
3/ To operate small components.
Charge with compressed air (slack oil) Piston at "8" [underlined] 220 [/underlined] lbs[symbol]”

This component will indicate the condition of the Power Circuit, and can be used to trace any failures, leaks, etc.

[underlined] Power Circuit Components and Positions [/underlined]
(a) Reservoir (b) Behind front Spar Pt. (c) To maintain head of fluid
(a) Distributer Block (b) Under reservoir (c) To take pipe connections
(a) G.T.C. (Byepass [sic] E.B.P. on test) (b) U/C. Nacelles. Aux. Panel. (c) Testing purposes.
(a) A.S.S.C. (b) Bulkhead (c) Seal off E.D.P. from circuit
(a) E.D.P. (b) Inboard. Engines (Triple Gear [inserted] N2 [/inserted]) (c) Constant supply of oil 8 1/2 gals min
(a) Vokes H.P. Filter (b) Rear Face, Front Spar (Nr. H. Tank) (c) Filter
(a) Auto. Cut out (b) Rear Face, Front Spar (c) Take load off pumps. & forms idle.
(a) Accumalator [sic] (b) Pt. Rear Face, Front Spar on fuselage. (c) See notes
(a) Hand pump (b) Pt. Side of accumalator [sic] (c) Operate small comp.

[underlined] U/C CIRCUIT [/underlined] WITH EMERGENC AIR


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(a) [underlined] Component [/underlined] (b) [underlined] Position [/underlined] (c) [underlined] Purpose [/underlined]
(a) U/C Control Box. (b) Rt. of Pilots seat (c) Selections "Up" & "Down"
(a) E.A.N.R.V. (b) Fitted to Conduit between U/C jacks (c) Blank [?] oil from U/C "Down" line Allows air to top of piston
(a) E.A.V. (b) Fitted below E.A.N.R.V. both U/C nucelles. (c) Opens vent for oil to atmos. from underside of jacks. Allows air to E.A.N.R.V.
(a) D.A.P.R.V. (1) Mk I (b) Pt. U/C nucelle (c) Thermal expansion
(a) Air Bottles (2) 1200 lbs[symbol]" (b) Rear face front spar. (c) Storage air in emergency
(a) E.A. Control lock. (b) Stbd side, rear face, front spar
(a) E.A. Control lock (later type) (b) Position same, remote control F/E Panel.
(a) N.R.V. (b) Between control valve and components (c) Prevent loss of air
(a) External Ch. Valve (b) Bomb Bay.
(a) Indicator (b) Pt. side of Pilots panel. (c) Warning lights.
(a) Warning Horn (b) Fuselage Pt. Side of pilot (c) Additional warning.

[underlined] Bleeding After Emergency Air. [/underlined]
1/ Put Selector Handle "Down"
2/ Turn "off" E/A.
3/ Jack up A/C. Connect Ground Test Rig.
[symbol] 5/ [symbol] Top up reservoir (and keep topped up).
4/ Release air through bleeder screw at top Jack.
6/ Pump oil into top of jack until air flows through bleeder screws and then close.

U/C has mechanical lock in up & down position and a geometrical in down position.

[underlined] Indicator lights. [/underlined]
Green – Fully locked Down
Red – Unlocked but not locked Down.
No lights – Fully locked up.

[underlined] Warning buzzer [/underlined] when inboard throttles are closed to within 1" to 1 1/2" of closed gate end and U/C is in any position than [underlined] locked down [/underlined]

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[underlined] FLAP CIRCUIT [/underlined] "LANCASTER"


(a) [underlined] Component [/underlined] (b) [underlined] Position [/underlined] (c) [underlined] Purpose. [/underlined]
(a) Control Handle. (b) Stbd of Pilots seat. (c) Select “Up” “Down” “Neutral”
(a) Control Vavle. (b) Stbd of Pilots seat. (c) Directs fluid.
(a) S.A.P.R.V. (2) (b) Attached to Control. (c) Thermal expantion [sic]
(a) Flap. Jack. (b) Behind rear Spar.

Flaps can be raised or lowered by compressed air. The raising of flaps must be done gently so as not to damage system and resevoior.

[underlined] No lights on indicators [/underlined] – U/C still held up, indicator wiring u/s, No 13 fuse blown
[underlined] Action [/underlined] Visual check, buzzer test, make further selection, check accum pressure, build up pressure with hand pump, use emerg. air as last resort.
[underlined] Two red lights on. [/underlined] check by buzzer, micro sw. may be iced up, make further selection
[underlined] Action [/underlined] check accum, try hand pump, use energ air as last resort
[underlined] Two red then 1 red & 1 green [/underlined]:- use buzzer, reselect.
[underlined] Action [/underlined] use hand pump, use emerg. air (Do same for 2 reds & 1 green on the old original)
1 green (change over switch)

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[underlined] BOMB DOOR CIRCUIT. [/underlined] "LANCASTER"


Emergency Air:- Main supply valve on top of bottle. [underlined] Ensure it is on before "Take Off" [/underlined]
Air bottle in bomb bay, foward [sic] bulkhead. Pt. side Control cock in B/A compartment near de-icing tank Stbd.

Pressure 1200 lbs[symbol]” Bomb doors can be lowered and raised [underlined] 4 or 5 times [/underlined] from emergency system. If emerg. air used a selection "down" or "up" must be made.

[underlined] HOT & COLD AIR INTAKES (CARB). [/underlined] "LANCASTER"


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Aircraft Instruments
Part II. Engine and Ancillary Services

In the first part of this article which appeared in last week's issue and dealt with the flight instruments (those six instruments grouped on the blind-flying panel) it was mentioned that engine instruments are equally vital; and two in particular, the engine-revolutions indicator and the boost-pressure gauge, are used in conjunction with the flying instruments, whilst the additional engine instruments, which indicate specific conditions of engine operation, are used only indirectly by the pilot and do not concern him objectively with controlling the flight attitude. Nevertheless, engine and ancillary service instruments are indispensable on modern aircraft.

Engine Instruments
The main instruments concerned with the engine are six in number, and although not grouped together on a standardised panel, as are the flight instruments, the engine instruments are usually arranged in close proximity to the flight panel so that they are under the immediate gaze of the pilot.

The engine revolutions indicator and boost pressure gauge are given pride of place, with the oil-pressure gauge and oil-temperature gauge adjacent. Close to them are mounted the engine-temperature gauge and the fuel-contents gauge with its fuel pressure feed warning light.

Instruments covering the functioning of ancillary services are placed in the most convenient position, the four chief instruments being the flap-incidence indicator, the undercarriage-position indicator, the wheel-brakes, air-pressure gauge, and the oxygen-supply gauge. The latter incorporates two indicators and a regular control in a single casing.


Revolutions Indicator
The R.P.M. Indicator in its simplest form is the centrifugal type. It operates on the same principle as the ordinary car speedometer, and although the latter measures the rate of revolutions of the camshaft or a part of the transmission system, the dial is calibrated in miles per hour. In the aircraft, the pilot needs to know his engine speed in terms of revolutions of the crankshaft per minute, and the instrument dial is calibrated accordingly. The dial scale is


figured in increments of two, and the indicated figure has to be multiplied by 100. Thus, when the dial needle points to the figure 16, the engine revs are 1,600 per minute.

Basically the centrifugal type of instrument consists of a gear wheel driving a small pinion on a governor shaft. The latter has a pair of weights linked to a fixed point at the head of the shaft and to a collar sliding on the lower part of the shaft. A spring between the top fixed point and the collar has a compressional permitting the weights to move uniformly in relation to the speed of shaft rotation. As the shaft is rotated at increasing speed, the weights move outwards due to centrifugal force,


and in so doing they draw the collar up the shaft against the spring.

A roller bears on the collar, and, according to movement of the latter, imparts motion to the indicating needle through a simple multiplying mechanism. The needle shaft usually carries a hairspring wound to provide sufficient tension to prevent backlash in the multiplying and hold the roller firmly against the collar on the governor shaft.

The arrangement of component parts in these instruments varies in different makes, but the general operating principle is common to all. The main disadvantage arises from the necessity of using a flexible shaft to transmit the drive from engine to instrument. Whilst this may present no difficulty in a single-engined aircraft, it assumes serious proportions in the case of multi-engined types where the outboard engines might be 20 feet or more from the cockpit.

Electrical Type
In such cases it is usual to fit an electrical revolution indicator, which employs a small generator drive by the engine. The generator is connected to the indicating instrument which is really a voltmeter. The dial is, however, graduated in revolution per minute instead of volts. The action of the instrument depends on the fact that the voltage produced by the generator is governed by the speed rotation. This type of instrument is simple and reliable but is not quite so accurate as the centrifugal type, although it is sufficiently accurate for all ordinary purposes.

The Boost-pressure Gauge [inserted] III [symbol][/inserted]
The boost pressure gauge indicates the pressure in the induction manifold at which the mixture is fed from super charger to cylinders. It thus provides the pilot with the information necessary for adjusting the power output of the engine for any desired condition of flight; it also

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AIRCR[missing letters]RUMENTS

enables him to guard against overloading the engine which would otherwise inevitably result in damage.

The gauge is operated by a simple aneroid-type movement, based on the differing pressures inside and outside an airtight diaphragm or capsule. As explained in the article on flight instruments, a capsule is a flat, hollow, circular metal container with concentric corrugations in each of its sides. When subjected to internal or external pressure it is sensitive and readily deformed. The deformation is employed to actuate the indicating needle through a multiplying mechanism, usually consisting of a rocker shaft connected to the capsule and driving a toothed sector which rotates the needle shaft.


The interior of the capsule in this instrument is completely exhausted of air, and the case in which the capsule is housed is airtight, with a connecting pipe to the induction manifold. Thus the pressure inside the instrument case is always that of the manifold, and fluctuations in this pressure will cause a corresponding variation in the deformation of the capsule.

The instrument dial is usually marked with either a coloured sector or a lubber line to denote the maximum permissible boost pressure for the particular engine concerned.

Oil Pressure
[italics] The Oil-pressure Gauge [/italics] is one of the most important engine instruments; it registers the pressure of oil circulating in the engine lubrication system, with its critical influence on optimum operating efficiency.

Owing to the fact that the gauge in the cockpit is usually situated at a considerable distance from the engine, a direct connection to convey oil from the lubrication system to the gauge is often impractical; for this reason a capillary line is employed.

The capillary line is a tube of very small bore, which connects into a Bourdon tube, i.e., a curved, flat, rectangular section tube which has the property of tending to straighten when subjected to internal pressure in excess of external pressure.

One end of the capillary tube is connected into that end of the Bourdon tube which is immovably fixed to the instrument case. The other (closed) end of the Bourdon tube is linked to a toothed sector which is capable of movement. The opposite end of the capillary is connected into the interior of a capsule which is externally subject to engine-oil pressure and housed in a chamber fitted into the lubrication system. The capsule, capillary and Bourdon tube are filled with a suitable liquid. When the capsule is compressed under the engine-oil pressure, the degree of pressure is transmitted via the capillary to the Bourdon and hence to the gauge. The tendency of the Bourdon tube

Diagrammatic sketch showing the operation of an Oil-pressure Gauge.

to straighten under internal pressure causes the toothed sector to impart a rotary motion to the indicator needle through the needle-shaft pinion. Backlash is controlled by a hair-spring wound on the needle shaft.

Dial, capillary and bulb of the Oil-temperature Gauge.

Oil Temperature
[italics] The Oil-temperature Gauge [/italics] employs a Bourdon tube and is somewhat similar in operation to the oil-pressure gauge. The Bourdon tube is connected by a capillary line to a thermometer bulb suspended in the engine lubrication system. Mercury in the bulb expands with a rise in temperature of the lubricating oil, and this expansion is communicated through the capillary liquid to the Bourdon tube in the gauge which, in turn, moves the needle over the dial of the gauge through the simple multiplying mechanism.

Fuel Contents
[italics] The Fuel-contents Gauge [/italics] on single-engined aircraft is actuated by the weight of fuel carried in the aircraft tanks. In the lowest portion of the tank is a transmitter fitting incorporating a capsule, the interior of which is connected by a capillary tube to another capsule located in the gauge.

Capsules and capillary are filled with a suitable fluid, and the weight of fuel in the tank, compressing the transmitter capsule, causes a proportionate expansion of the gauge capsule. The movement of the gauge capsule is utilised to actuate the indicator needle through a multiplying mechanism.

On multi-engined aircraft an electrically operated fuel contents gauge is usually employed. This type of apparatus incorporates an electric transmitter unit in the fuel tank, connected by a 5-core cable to the gauge in the cockpit.

The system consists basically of a float in the tank which operates a variable transmitter resistance in a series of circuits supplied with current from the aircraft battery. Three tappings on the resistance are connected by cables to three coils in the instrument which, when energised, actuates a permanent magnet connected to the indicating needle.

Perspective section through transmitter unit and indicator mechanism of the Fuel-contents Gauge.

Fuel Warning
[italics] The Fuel-feed Warning Light [italics], which is fitted adjacent to the fuel-contents gauge, is lighted when the flow from fuel pump to carburettor is faulty. A line tapping is taken from the feed pipe between pump and carburettor and is connected to a unit incorporating a diaphragm and electric

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contact points. The contact points are wired up to the aircraft battery and the warning light; they are held apart by pressure under the diaphragm. If, however, the fuel feed is faulty, the drop of pressure in the feed line causes the diaphragm to lower and bring the contact points together, so lighting the warning lamp.

Engine Temperature
[italics] Engine-temperature Gauges [/italics] used for liquid-cooled engines differ from those used on air-cooled engines. Whereas the temperature of a liquid-cooled engine is taken from a point in the coolant system, the temperature of an air-cooled engine is taken from one or more of the cylinder heads. In either case the information is necessary to safeguard against under- or over-cooling of the engine for any particular operative condition.

Section showing diaphragm and contact points for Fuel Feed Warning Light.

The temperature gauge for a liquid-cooled engine is operated by a sensitive bulb immersed in the engine-coolant system; the bulb is partially filled with a volatile liquid, the remaining volume being filled with saturated vapour. Immersed in the liquid is the end of a capillary tube (itself filled with liquid), which is connected to the Bourdon tube in the gauge.

If the engine-coolant temperature rises, the pressure of the saturated vapour increases proportionately, and is transmitted to the gauge through the liquid in the capillary and the Bourdon tube, thus actuating the indicating needle through the usual multiplying mechanism.

On air-cooled engines a thermos-couple incorporating two dissimilar metals (e.g., constantin and copper) is fitted to a suitable part of the cylinder head, and wires are taken from the unit to a milli-volt meter calibrated as a thermometer gauge on the instrument panel. Usually more than one thermos-couple is fitted.

When the thermo-couple is heated, an electromotive force is generated, and the current is passed through a coil of fine wire mounted on a rotatable soft-iron core, between the poles of a permanent magnet in the casing of the thermometer gauge. The coil and the iron core are mounted on jewel bearings, and are connected to the indicating needle of the instrument, which moves over the calibrated scale according to the strength of current generated by the thermos-couple.

Radiator thermometer and indicator movement for liquid-cooled engines.

Indicator element for thermo-couple cylinder-head temperature gauge.

Ancillary Service Instruments

Flap Indicator
[italics] The Flap Incidence Indicator [/italics] gives an accurate definition of the precise position of the flaps. Consequently it is of considerable importance to the pilot during the approach and landing. In small aircraft a simple, mechanically operated indicator may suffice, but in large aircraft, where the cockpit may be situated at some distance from the flaps, a mechanically operated indicator is out of the question.

One of the most modern systems for the electrical indication of flap incidence is the Desynn. In this, a small electrical transmitter is fitted at some convenient point on the flap-linkage gear, with wires taken to an electric indicator on the instrument panel.

Current is supplied by the aircraft battery to a transmitter consisting of an arm with two contacts rotating on a ring-type resistance. The arm is connected by links to the flaps, and accordingly moves to whatever position of the flaps is selected. Three wires are taken from tappings on the transmitter to the three coils which energise the ring-type stator of the indicator; rotating within the stator is a pivoted permanent magnet carrying the indicating needle, and according to the position of the arm in the transmitter, the direction and distribution of current to the coils in the indicator turns the permanent magnet to a position relative to that of the transmitter arm, and the needle thus indicates against degrees on the dial the position taken by the flaps.

Diagram of the basic elements and connections in the “Desynn Flap Incidence Indicator.

[italics] The Undercarriage-Position Indicator [/italics] is, of course, only fitted to aircraft employing retractable undercarriages, and provides the pilot with positive information as to whether the landing gear is locked safely in the “up” or “down” position.

The indicator usually comprises red and green windows in a dial fitted on the instrument panel. The indicator described has six windows, the upper three being red and the lower three green. Behind these windows are small electric bulbs wired in circuit with the aircraft battery and switches located on the undercarriage legs. The windows on the left-hand side relate to the port undercarriage, while those on the right-hand side are for the starboard undercarriage; top and bottom windows are used where retractable nose and tail wheels are fitted to the aircraft.

Indicator panel for showing safety positions of undercarriage.

When the port and starboard undercarriage legs are safely locked in the “down” position, the windows at each side are illuminated green, but when the undercarriage is being retracted, the upper port and starboard windows are illuminated red, and will continue to be so illuminated

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until the undercarriage is retracted safely home and locked, when the red lights disappear.

While the red lights are seen, the pilot will have clear evidence that the undercarriage is in a semi-retracted position, and that it is thus unsafe to land. The diagram illustrates the circuit between the light bulbs, the switches on the undercarriage, and the warning horn which sounds in the cockpit should the undercarriage be operated incorrectly.

Wiring circuits layout for Undercarriage Position Indicator and Warning Horn.

Should any of the green lights fail at a vital moment, a knob in the centre of the dial can be pulled to change the electric circuit over to a new set of bulbs. The strength of illumination through the indicator windows can be adjusted for day or night flying by rotating the central knob; in addition to its function for changing over to a new set of bulbs, this knob controls a circular, translucent shade behind the windows which can be brought into use to provide dimming.

Brake Pressure
[italics] The Brake-Pressure Gauge [/italics] registers the available pressure of compressed air in the container as well as the braking pressure applied to each or both wheel brakes.

Wheel Brake Pressure supply and application indicator, and (right) the wheel brake system showing connection reference points between container, relay valve, indicator, and brakes.

A single dial, calibrated with three separate scales, is mounted in the cockpit. Indications are given by three separate needles, individually actuated by three Bourdon tubes housed behind the dial.

The Bourdon tubes are each connected by pipe-line tappings into the appropriate supply lines between brakes, container and relay control valve, as illustrated in the braking-system diagram.

The Oxygen Supply Indicators and Regulator Control fitted on self-contained panel.

Although only indirectly concerning the instrument [italics] per se [/italics], a brief explanation of the braking system might be of interest.

The system illustrated in the Dunlop, which enjoys wide-spread use. The braking elements themselves are of the type commonly known as “internal expanding,” the shoes being forced into contact with the brake drum to supply very high frictional resistance to rotation of the wheel. The shoes are located by grooves which prevent any movement other than radial, and are carried on a collapsible rubber tube which, with the introduction of compressed air, swells and so forces the shoes into contact with the drum.

Section through Regulator Control showing pressure-reducing valve mechanism.

Differential braking is obtained by the incorporation of a relay control valve linked to the rudder control. This valve, according to the position of the rudder bar, permits a greater volume of air to be supplied to one wheel than to the other, or if the rudder is centralised, to supply each wheel equally.

The air supply from container to relay valve is governed by a trip lever mounted on the control column. Thus the pilot can, by correlating the adjustment of trip lever and rudder bar, control the strength of braking applied and the distribution of the braking effort.

Oxygen Supply
[italics] Oxygen-Supply Indicators [/italics] are incorporated with a regulator control, by means of which the user can adjust the delivery of oxygen according to his needs for the height at which the aircraft is flying. Additionally to this, the pressure of the supply to the individual must be constant, even though the volume is variable, and this constant pressure must be maintained despite drop of pressure in the storage bottles after continuous use.

The small panel carrying the oxygen instruments has one dial indicating the quantity of gas in the bottles. Another registers the correct flow of gas to the face mask for any altitude up to 40,000ft., after the user has suitably manipulated the control screw for the altitude of the aircraft.

An ingenious mechanism is fitted behind this panel for dropping the gas pressure delivered by the bottles down

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to 11-15 lb./sq. in. Referring to the diagram, oxygen from the bottles enters at A and passes the filter B and valve C to the chamber D. One wall of this chamber consists of the diaphragm E, which butts against the strong spring F. A small bell crank lever G is held at its lower end against the diaphragm by a light spring H, and at the upper end is connected to the valve C.

Oxygen under pressure enters the chamber D and forces the diaphragm outwards against the spring F. In doing this it operates the bell crank lever, closes the valve C and cuts off the oxygen feed from the supply at A. As oxygen is drawn off from the chamber D, the pressure in the chamber drops until the diaphragm deflects enough to open valve C and restore the pressure to 11-15 lb. Actually, the diaphragm vibrates at high periodicity, causing the valve to open and close a very small amount at a very high speed, so feeding small quantities of oxygen into the chamber.

Gas from the chamber D passes through the control valve to a small flow-meter operating the altitude/delivery indicator, and thence to the user’s oxygen mask.

[background page fully included later]

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The Tandem Monoplane
An Answer to the Editor


[background page already included earlier]

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U/C "Down" 20 seconds "Up" 18 seconds.
Emergency Air 6 seconds.
Flaps "Down" 7.5 Seconds.
Bomb Doors "open" 6 Seconds "Closed" 7 seconds

[underlined] INSTRUMENTS [/underlined]
[underlined] OIL PRESSURE GAUGE [/underlined]:- Transmitting Type.


Consists of 3 Parts:-
1/ Pressure banjo union
2/ Indicator – Yellow Begal – edgewise scale 0-150
3/ Connecting capillary of anneald copper tube, sometimes braided. This connects indicator to banjo union.

1/ Transmitting fluid is ethyl alcohol and will not freeze at altitude [inserted] F.P. - 130°C [/inserted] Also gives immediate reading.
2/ In the event of breakage no oil or pressure will be lost from system.
3/ Not affect be[sic] heat.

[page break]

[underlined] OIL TEMPERATURE GAUGE [/underlined]:-
(Steel bulb because of action of metal & mercury)


[underlined] FUEL PRESSURE WARNING LIGHT [/underlined]:-
Resistant Unit


Shows a red warning lamp when pressure drops below that of a safety factor. When pressure is reached the light goes out. This light will not show unless it is switched. Fuses fitted for 24v & 12v supply.

The pressure unit is fitted between pump and carb.

[page break]

[underlined] RADIATOR TEMPERATURE GAUGE [/underlined]:-


Bulb fitted in coolant header tank.

Filled 2/3 with Ethyl Ether so if inverted tube will remain below the liquid.

Worked on saturated vapour pressure due to change in coolant temp. Boils at 34.6°C

[underlined] TANK UNIT TRANSMITTER [/underlined]


[underlined DESYNN FUEL CONTENTS GAUGE [/underlined]:-
Consists of 2 Units:- a) Tank unit which acts as transmitter
b) Indicator, single pointer which returns to "off" scale position when switched "off" by small magnet.

[page break]

Limiting resistances in power leads are to cut down current to Toroidal[?] resistance, and cuts down possibility of sparking and fire from gases in tank.

Can be used on 12v or 24v supply


Desynn Position Indicator
Used to show position of flaps, gills, trimming tabs etc. Principle same as for fuel gauges. In all indicators pointer returns to "off" position by means of a weak two poled mag. mounted above rotor. The mag. is fixed perm. in "off" position scale and when current is switched "off" the rotor lines itself up with with [sic] the weak mag.

Mark IV Elec. Engine Speed Indicator
Consists of 3 parts. 1/ Flexable [sic] drive (1/4 engine speed).
2/ Generator – fitted on bulk head. (Gear 2:1). 3/ Indicator. The polarity induced in the Staloy laminations of S.S. [indecipherable word] motor does not become stabalised [sic] until approx. 600 R.P.M. Frequency governs indicator and not speed of motor.

[inserted][underlined] Indic [/underlined][/inserted] The rotating magnetic field produced in the coils produce an E.M.F. in the squirrel cage which causes it to rotate due to induced mag. field of squirrel cage. It is made synchronous by two steel pole pieces on the outer edge of rotor which takes off over when the edge [deleted] of the rotor [/deleted] of the cage has caught in the mag-field, as at that speed there is no induced E.M.F. or mag-field in the cage due to its not being cut by rotating field

[page break]

[underlined] MARK IV ELECTRIC ENGINE SPEED INDICATOR [/underlined]:-


[page break]

[underlined] BOOST GAUGE [/underlined]:- Mk III


Safety Factor:-
1/ Choke at inlet (Prevents surging) (eg. back firing)
2/ Filter inside connector (to protect mechanism from dirt).
3/ Triplex Glass. (withstand pressure)
To indicate pressure above and below normal atmospheric pressure of mixture in induction manifold.
Range in lbs/[symbol]" -4 to +20.
Rubber Ring set at "max Boost level flight"

[page break]

[underlined] ELECTRICS [/underlined]:-
Essential Parts 1/ Complete Circuit
2/ Pressure Difference
3/ Insulations

Electricity produces:-
1/ Formation of magnetic field
2/ Heat
3/ Chemical action – ELECTROLYSIS.

Unit of Pressure. – Volt (Electro Motive Force) E }
Unit of Current – Ampere [symbol] I }
Unit of Resistance – Ohm [symbol] R } *
Unit of Power – Watt (746 watts = 1.H.P.) W }
The hotter, longer and thinner, the greater is Resistance

[underlined] OHM'S LAW [/underlined]:-
If a current is flowing in a conductor, which is kept at even temp., then that current is directly proportional to the Electro Motive Force (Voltage) and inversely proportional to the resistance.


Series Connection:-


Current throughout whole circuit is the same, that is it does not matter what the volume of resist are, the current flowing through them is the same. However the value of stat resist as shown above.

[page break]

Parallel Connections:-


Wiring up resist in parallel the total voltage drop is deliberately applied accross [sic] each hense [sic] the amount of current flowing through each will be governed by the value of resist. (Ohm’s law).

Series and Parallel Connections.


[page break]

[underlined] LEAD ACID CELLS [/underlined]:-


Fully charged (Open circuit) 2.2v.
Fully charged (On load) 2.0v
Discharged (On load) 1.8v Must never go below.

Ampere Hours 40.A.H.
a) 10 hour rate 4 [symbol] for 10 hours (A/C Acc 12v 40 A.H.)

[underlined] Cells in Series [/underlined]:-
Each cell equal to 2v 4.A.H. No of cells. 6.
Voltage of 1 cell .2
Voltage of 6 cells = 2 x 6 = 12v
Capacity 40 A.H.

Cells in Parallel.
Each cell 2v 4.A.H. Voltage of 1 cell 2v.
Capacity of all 240 A.H.


[page break]

[underlined] GENERATOR:- DC. [/underlined] (Shunt[?] Wound) 24v 1500 Watts
1/ Yoke (Stator)
main frame, field windings, field magnets


2/ Armature
Soft iron slatted core. and insulated copper conductors
Commutator – changes A.C. to D.C.
3/ Brush Gear
Pick up current.


Output depends on:- (E.M.F.)
1/ Length of Conductor
2/ Field Strength (Determined by current).
3/ Speed.

[underlined] Carbon Pile Reg [/underlined]:- When a constant voltage is required an increase of speed is counteracted by reducing field strength

[page break]

[underlined] ACCUMALATOR CUT OUT [/underlined]:-


[underlined] NEWTON CARBON PILE VOLTAGE REGULATOR:- [/underlined]


Purpose:- G-
V.Regulator:- To regulate voltage of E.D.G. to 29v. for varying speeds of engine.
Current Unit:- Prevents over loading of generator by reducing its voltage output. When over load conditions are imposed on circuit The enables [sic] acco.[?] to share load.

[page break]

[duplicate of page included earlier]

[page break]

[Background page included earlier]

[underlined] Ident BLUE Band [/underlined]

Temp. Min 60°
Max Climb (1 hr) 125
Econ. Climb (Cont) 105
Combat 135

Coolant pump driven of [sic] [underlined] lower [/underlined] vertical drive connected by MUFF Coupling

Thermostat. assist warming up Prevent rapid cooling

Teddington Thermostatic relief valve 32 1/2 lbs.
Press 70/30 boils 135°c freezes -15°c
No Press 103.5 freezes -15°c [/inserted]

[page break]

[duplicate of page included earlier]

[page break]

[Background page included earlier]

[inserted] Rad flaps.
Electro Pheumatic [sic] Jack air operated both ways

Energises thermostatic switch piston retracts & opens shutter
Open [underlined] 105° [/underlined] Close 99°
Override Switch fitted

Saturated vapour pressure due to change in cool temp
Boils 34.6°c


Temp Gauge
1 m.m. capillary tube
Range 40° - 140° [/inserted]

[page break]



If A.C.O. or Fuse goes, then light will be on, and current will flow through Rectifier (least path of resist.) If E.D.G. goes, current will flow from accs. through resistance as Rectifier is one way only. Resist 18v + 6v. lamp = 2AV. [symbol] light will just glow.
Purpose:- Shows red warning light when any of following conditions:-
1/ Generator fails to function.
2/ Main fuse blows.
3/ Cut-out contacts open.



[page break]


[underlined] TYPICAL AIRCRAFT CIRCUIT [/underlined]:- LANCASTER.

[page break]


[underlined] TYPICAL FEATHER PUMP MOTOR CIRCUIT [/underlined]:-


[page break]

PHASE "O" [underlined] ENGINE STARTING DRILL [/underlined]:- 19/5/4[missing number]

1/ Check:-
1/ Chocks in position
2/ Covers and ropes removed
3/ All obstructions cleared, & no loose panels.
4/ A/C to wind
5/ Check external accs.

2/ On Entering A/C.
1/ Check internal accs.
2/ Turn main switch to "flight" (Check fuel contents)
3/ Balance cock to "Off"
4/ U/C lever to "Down" (lights – green)
5/ Mags. "Off"
6/ D.R. Compass "On"
7/ Switch on fuel contents gauges
8/ Check contents and see [underlined] red warning [/underlined] lights [underlined] "On" [/underlined]

3/ Check following:-
1/ Flap lever "Neutral"
2/ Brakes "On" (80 lbs/[symbol]" each wheel)
3/ Air Intake "Cold".
4/ Supercharger "M" Gear.
5/ Boost Cut-Out "Normal"
6/ Prop. Increased R.P.M.
7/ Throttle 1/2" Open.
8/ Radiator Shutters "Open"
9/ Bomb doors "Closed"

4/ 1/ Select Fuel tank, turn on master fuel cock for eng. required
5/ Switch on pulsometer pumps if fitted
6/ Main switch to "Ground"
7/ Get "All Clear" from ground crew.
8/ Switch "On" main mags & booster coil
9/ Give order to ground crew ready for starting
10/ Ground crew reply "Ready"
11/ Give order "Contact"
12/ Press Starter button for 10 seconds with 30 seconds intervals before attempting again.

[page break]

As engine turns, ground crew primes (In cold weather continue priming after engine has started if necc.)
13/ Ground crew turns "off" priming cock, and screws down priming pump.
14/ Turn "Off" booster coil, note oil pressure.
15/ Turn main switch to "Flight"

1/ Engine R.P.M. 800 – 1000.
2/ Check magnetoes.
3/ Engine R.P.M. 1000 – 1200 for warming up.
4/ Check Hydraulics by operating flaps.
5/ Switch "off" pulsometer pumps if fitted.
6/ a) Ensure engine coolant temp is at 60°c }
b) Ensure engine oil temp is at 15°c } before opening throttle 0 lbs boost.
7/ Exercise prop. operate R.P.M lever down and up twice.
Note rise and fall in revs.
8/ Operate prop. lever (R.P.M.) to give a drop of 300 R.P.M.
9/ Move throttle lever so that boost press. varies 1 lb each way R.P.M. should remain constant (test for C.S.O.)
10/ Move R.P.M. lever to "max" R.P.M.
11/ Change to "S" Gear. Note slight rise in boost pressure and drop in R.P.M.
12/ Change back to "M" gear.
13/ Open throttle to "take off"
14/ Check boost pressure and R.P.M.
15/ Throttle back to gate, check boost & R.P.M.
16/ Check mags. Normal 40 – 50 R.P.M. drop. Max 100 R.P.M.
17/ Throttle back to slow running and check that engine does not cut.

1/ Open up to 800 – 1000 R.P.M.
2/ Allow engine to idle for 2 minutes
3/ Close master fuel cock. (this operates cut out on Lanc. & Halifax)

[page break]

[background page included later]

[inserted]THE hallmark of a good pilot is the manner in which he checks every detail of his aircraft before he leaves the ground. One can see ground staff getting quite impatient sometimes when a test pilot has sat himself in the cockpit apparently ready to take off, only to spend at least five minutes doing, to the casual observer, very little. It is easy for a pilot to skip these apparently routine checks, but it is noteworthy that the really experienced and apparently carefree pilot invariably makes it a ritual.

On a large aircraft there are many checks to be made before take-off. Those on the engine, which are covered in this article, are possibly amongst the most important, although one check omitted out of all of them will leave a weak link in the chain, and no one check can be said to be less important than any other.

Ground Running of Aero Engines
by J.A. KYD

The Right Position
Let it be assumed that the pilot has just climbed into the cockpit of a single-engined fighter with its wheels choked and its nose pointing into the wind to get the benefit of increased cooling. Before starting the engine he will look round to see that the slip-stream from the propeller will not blow dust on to any aircraft parked behind him. The ground crew will have placed the aircraft so that the nose is not directly over any loose gravel which might be sucked into the propeller blades during the engine run.

Fuel and Ignition
The pilot will check the fuel in his tanks on the contents gauge, ensure that wheel brakes are on, turn on his fuel cocks, set the throttle to a position very slightly away from the rearward position and the propeller speed control to the fully-forward position (unless a de Havilland bracket-type propeller is fitted, when the control is placed in the fully-rearward position), set the mixture control to the “rich” position, if a two-speed super-charger is fitted he will ensure that the charge-speed is in the “M” position (low gear), and, finally, he will check that his air-intake control is set to the “cold” position. The ignition must not be switched on yet, for the ground crew have to turn the engine over two or three times by pulling on the propeller blades. This serves the dual purpose of breaking down oil drag and of ensuring that there is no evidence of “hydraulicing.” The latter occurs only in engines which have inverted cylinders, and is caused by oil or petrol draining into the cylinder heads and opposing the travel of the piston towards the cylinder head. Serious damage would occur to the engine if this was not discovered before it fired.

Starting Up
The pilot is now ready to start the engine, and he therefore switches on the ignition. To ensure that atomised fuel reaches the cylinders and that a fat spark is provided at the sparking-plug, the pilot works a priming-pump plunger, to inject fuel into the cylinders, and switches on a booster coil at the same time as he operates the starter. When the engine starts he releases the starter, but continues priming, and does not switch off the booster coil until the engine is running evenly.

As soon as the engine is running the pilot watches his oil-pressure gauge to ensure that the oil is circulating through the engine. He then lets the engine run for a few minutes, but at the same time increases the throttle opening gradually until the engine is running at a fast tick-over. (The propeller speed-control lever for a de Haviland bracket-type propeller would have been moved to the fully-forward position during this period.)

When the pilot observes that his oil temperature is satisfactory and that his cylinder-head temperature, in an air-cooled engine, or his coolant temperature in a liquid-cooled engine, is at the correct figure, he lets the wheel brakes off for a moment to allow the aircraft to press firmly against the chocks, and then opens the throttle to a medium boost and checks that his supercharger gear change and his propeller are both functioning correctly. The super-charger gear change is checked by moving the control lever into the “S” (high-speed) position and noting that either the r.p.m. indicator needle moves slightly or that the oil-pressure gauge needle flickers, depending upon the type of engine. The automatic boost control prevents the results of the change being shown on the boost gauge. The gear-change control lever is returned to the “M” position when the pilot is satisfied that the mechanism is functioning properly. The constant-speeding qualities of the propeller are checked by retracting the speed control lever until the r.p.m. commence to drop as shown on the engine-speed indicator. The propeller-speed control lever is then returned to the fully-forward position.

During the above tests a close watch will have been kept by the pilot for any signs of vibration, and if there were any evident the ground crew will be acquainted with the exact symptoms to enable them to track the cause of the trouble.

The pilot then checks the engine performance at full throttle with the propeller-speed control lever in the fully-forward position. When a small-range (20 degrees) constant-speed propeller is fitted, this check is simple,


since the propeller will not have sufficient travel in the fine-pitch direction to allow the maximum permissible take-off r.p.m. to be attained, and the blades are consequently held against their fine-pitch stops. The pilot will know what r.p.m. to expect when at his take-off boost, and any loss of power will at once be evident in the shape of a drop in r.p.m. When a wide-range (35 degrees) propeller is fitted the check is usually made at about the highest boost that will still retain the blades against their fine-pitch stops, and the pilot will know from experience what r.p.m. to expect. If the check was made at full throttle the propeller would be constant-speeding, and any drop in power would be camouflaged by the blades going into a finer pitch to maintain the engine speed.

The final check that the pilot makes is to ensure that each of the magnetos is functioning properly. He does this, at a lower boost than take-off, by switching off each magneto in turn and checking that the r.p.m. do not fall, when the engine is operating on either magneto, by more than about five per cent of the speed.

Only when he is satisfied that all the above tests have been completed properly will the experienced pilot take off.

[page break]

[background page included earlier]

[inserted] Aero-Engine STARING SYSTEMS

THE modern aero-engine, owing to its large size and power output, presents much more difficulty in starting than the light engines of a few years ago. To “swing the prop,” as on a Tiger or a Piper Cub, is not, of course, a practical proposition, and mechanical or other aids are necessary.

Starters fall into three main categories: mechanical (including hand starters), electric starters and gas or cartridge types.

Fig. 1. Diagram of hand-operated Inertia Starter.

Whatever type of gear is adopted, two conditions are first required: (a) the induction system must be primed with fuel to ensure a quick response; (b) the ignition system must provide a good fat spark to fire the mixture.

These two points are taken care of by providing a priming pump which draws a small squirt of neat fuel from the tanks and shoots it into the cylinders to provide an initial charge, and by providing a starting magneto which gives a continuous stream of sparks at very low speed. This magneto is connected through the distributors of the main magnetos, and is switched off when the main magnetos are running fast enough to generate their own current.

Mechanical Starters
The first, and probably the simplest, form of starter is that shown in Fig. 1, and known as the inertia or impulse type. It is a development of the flywheel-driven toys we used to see before the war.

As will be seen from the sketch, it consists of a flywheel which is rotated, by the handle, through a set of gears. The handle is cranked until the flywheel is running at about 10,000 r.p.m. then removed or released and the clutch engaged. Owing to the energy stored up in the spinning flywheel the engine is turned fairly fast for a few revolutions, and will usually fire and start immediately. A ratchet gear is used to enable the engine to overtake the driving gears and run free.

Another form of hand starter is that in which the engine is driven direct by the crank. In this case the gear ratio is arranged to enable the average mechanic to turn the engine without undue exertion; as in the other type, a ratchet or free-wheel is used.

Electrical Systems
When electric starters are fitted they may be of two kinds – either a large edition of the familiar car-starter or an electrification of the inertia type already described.

Of the first type little need be said except to point out that owing to the heavy current required the power is normally provided from a large “ground battery” mounted on a truck and plugged into a socket to start the engine. The socket is of a special type, and must be turned round to be connected; this turning is arranged so as to disconnect the aircraft’s own battery when the ground battery is plugged in (Fig. 2.)

Fig. 2. Wiring Diagram for Electric Starter with Ground Battery.

In the case of the inertia starter, the electric motor is used only to spin the flywheel, and need not be quite so large. The switch is in the form of a knob, and is pushed in to energise the motor, held in till the flywheel runs up to speed, then pulled out to engage the starter clutch and switch off the current. An example is the Tomahawk.

A separate booster coil is frequently used in connection with electric starters in place of the starter magneto, the leads from the coil passing into the main distributor as before and providing sparks before the main magnetos are up to speed.

Gas and Cartridge Starters
The original gas starter system is not very often met with nowadays, but it is described as it is of interest. Compressed air, carried in a cylinder, is admitted by means of a hand control to an atomiser, in which it is mixed with petrol, and by reason of pressure, quickly fills a distribution system with an air-gas mixture. This distribution system admits the gas to the cylinders in correct order.

The hand-starting magneto is then rotated smartly by hand, and, as the piston of at least one cylinder must be in the firing stroke position, the engine is driven round until it fires and runs on its normal induction system.

The remaining system is the cartridge starter as fitted to certain Merlin-engined Spitfires. A magazine containing about six cartridges is used, coupled to both a loading and a firing mechanism. The cartridge is charged with a chemical which liberates a high-pressure gas into a pipe connected to a small turbine.

This turbine is coupled to the engine in the same manner as a direct-starting motor, and drives the engine through gearing. In order to permit several starts the magazine may be rotated by means of a pull-wire, to bring the next cartridge into the breech for firing. Firing is usually done by electric spark. This system is rapidly gaining ground, and has the great advantage of simplicity and light weight. [/inserted]

[page break]

4/ When engine has stopped turning switch “off” mags
5/ Before leaving A/C (I) Switch off all elec. circuits
(II) Switch off all fuel cocks.
6/ Turn main switch to ground.

If leaving A/C for a considerable time, disconnect accs.
[underlined] Before take Off:- [/underlined] Check 1/ [indecipherable word] struts removed
2/ Pito head cover removed
3/ Escape hatchs & door fixed securely

[underlined] Engine fails to turn [/underlined]:-
1/ U/S Accs 2/ Sticky Solenoids 3/ U/S Fuse 4/ U/S Circuit or Motor 5/ U/S Switches (Dirty contacts).

[underlined] Engine fails to start:- Ignition [/underlined]
1/ U/S H.S.M. Switches 2/ Isolated spark gap – oil insulating contacts or cracked sleeve 3/ U/S H.S.M. or Booster coil 4/ Defected lead 5/ Incorrectly fitted Contact breaker cover. 6/ Normal H.S.M. C.B faults

[underlined] Priming:- [/underlined]
1/ U/S Priming pump. 2/ Under or over primed. 3/ Broken or restricted pipe line. 4/ Blocked atomiser or filter.

Engine fails to Pick up:-
1/ Incorrectly set throttle control.
2/ Master fuel cock "off"
3/ Insufficient fuel pressure
4/ Slow running jets blocked

[underlined] Incorrect Oil Pressure [/underlined]
[underlined] High [/underlined]:- 1/ High viscosity due to cold engine
2/ Incorrectly set C.R.U.
3/ Faulty gauge.
[underlined] Low [/underlined]:- 1/ Low viscosity due to high temp
2/ Incorrectly set C.R.U.
3/ Faulty Gauge
4/ Badly worn bearings.
5/ Leak on suction side of pump.

[page break]

[underlined] Incorrect Oil Temp [/underlined]:-
High:- 1/ Insufficient in tank
2/ [indecipherable word] viscosity valve U/S.
3/ Slugded [sic] up cooler
4/ Fauly gauge.

Low :-
1/ Faulty gauge

High or Low.
Re-adjustment of radiator shutter

[underlined] Incorrect Coolant Temperature [/underlined]:-
1/ Insufficient coolant in system.
2/ Air locks in system.
3/ Obstruction in pipeline
4/ Coolant pump drive sheared, or faulty gland allowing air in.
5/ Radiator shutter closed
6/ Radiator blocked (Outside or inside)
7/ Faulty thermostatic by-pass
8/ Nose not into wind
9/ Faulty gauge.

1/ Thermostatic by-pass U/S
2/ RAd [indecipherable word] joined OPEN.
3/ Faulty gauge.

[underlined] Blue [/underlined] smoke from exhaust:- (Oil)
1/ Broken or gummed up scraper rings.
2/ Rings incorrectly spaced
3/ Worn cylinders or pistons
4/ Cracked throttle butterfly or oil seal u/s

[underlined] White [/underlined] vapour from exhaust (Yellow flame)
Internal coolant leak.

[underlined] Engine Vibrates [/underlined]:-
Prop:- 1/ Damage to blades
2/ Out of track
3/ Incorrect assembly when meshing
4/ Loose on shaft

[page break]

General:- 1/ Engine loose in mounting
2/ Worn bearings
3/ Misfiring
4/ Loose engine bearing bolts.

Engine cuts when one mag is switched "off":-
1/ Dead mag
2/ Contact breaker:- a) Broken spring
b) Points stuck open (Rocker arm seized)
c) Worn [indecipherable word] heel
d) Defective switch on switch lead
e) Grease behind primary pick up.

Excessive drop in R.P.M. when one mag switched "off".
1/ U/S Plugs.
2/ Faulty leads or U/S spark intensifier
3/ Sticky rocker arm.
4/ Dirty points
5/ Weak C.B spring
6/ Cracked distributer [sic] block.
7/ Faulty [deleted] leads [/deleted] Mag. timing

1/ Cold engine
2/ Weak mixture
3/ Crossed leads.

Unsteady R.P.M:-
1/ Faulty C.S.U.
2/ Sticky Rev. [indecipherable word]
3/ Tac. drive (frayed or dry cable).
4/ Gusty winds

Incorrect Boost Reading:-
1/ Leaking pipe line.
2/ Incorrectly adjusted A.B.C.
3/ A.B.C. aneroid burst

[page break]

4/ Dirty flame traps (Boost high.)
5/ "Hot" & "Cold" air intakes to "Hot".
6/ Sticking relay piston or linkwork (Gives jerky reading)
7/ U/S. Gauge.

Loss of Power:- (Due to over heating)
1/ Weak mixture. (Wrongly adjusted needles, or capsule burst) [inserted] about +4 [/inserted]
2/ Loss of compression 1/ Piston & cyls.
(Does not cause overheating) 2/ U/S Rings. 3/ Worn valves or seats, or sticking valves 4/ Broken valve springs. 5/ Incorrect tappet clearance. 6/ Leaking plug inserts.

Rich Mixture:- Black smoke.
1/ Over priming
2/ Altitude capsule bursts (Shows at altitude)
3/ Priming [indecipherable word] left on.
4/ Fuel level too high (a) Fuel logged[?] float (b) Worn float needle.

1/ Incorrect mixture
2/ Incorrect fuel.
3/ Too high a compression ratio.
4/ High boost with low revs.
N.B. May be seen as a long orange flame with puffs of black smoke

1/ Incandesant [sic] carbon.
2/ Local over heating – hot spots.

[page break]

[underlined] Faults of D.H. Hydromatic Prop:- [/underlined] (Mechanical, Oil & Electrical)
1/ Distrib. spring – no change unless below 450 lbs press. (P.O.C.O.S. 450 lbs)
2/ C.S.U. Spring – Prop courses [sic] - R.P.M. decrease
3/ C.S.U. Drive – Prop fines – R.P.M. increase. If it rises above 3000 then throttle back if not then feather.
4/ R.P.M. control broken -
Engine end – Prop goes course [sic].
Cockpit end - Hold in previous setting

[underlined] Oil Faults [/underlined] – can loose [sic] [underlined] all [/underlined] oil in the engine [symbol] C.T.M. will put prop into fine pitch. (Max. R.P.M.)
2/ Faulty oil seals – fluctuating R.P.M. on surging of engine.

[underlined] Electrical [/underlined] – 1/ feathering button fails to snap out – Prop would feather and unfeather – try again, if not pull fuse out
2/ P.O.C.O.S. set too low – would start to feather but would be forced back by C.T.M.


[page break]

Principle of Operation:-
Reciprecating [sic] motion of the piston has to be converted into rotary movement of the blades. This is achieved by bevals [sic] on the blade roots and base of cylindrical cam members. This member acts as an intermediate between the reciprecating [sic] motion of the piston and rotation of the blade roots.

Rollers secured to piston slide in helical slots in cam cylinders.

To obtain the neccassary [sic] travel and also to prevent the piston moving unduly the rotating cam cylinders turns inside another fixed one having slots cut in the opposite direction.

These slots are known as dog legged cams, the 1st angle covers the constant speeding range of 35°. 2nd angle covers the feathering action range of 45°
Extra high pressure to force the piston over the 2nd angle is supported from an ancillary oil pump.

[underlined] Under speeding [/underlined]
Oil fed to front of piston from C.R.V. at 80 lbs[symbol]" (Normal Engine oil pressure) + C.T.M. turns blades to fine oil from rear of piston returns to sump via C.S.U.

[underlined] Over Speeding [/underlined]:-
If in under speeding boosted engine oil fed to rear of piston via C.S.U. turns blades to course (pressure 180 – 200 lbs[symbol]") Oil from front of piston returned to C.R.V.

[underlined] Feathering [/underlined]:-
External supply of oil from main tank is boosted to 400 lbs[symbol]" This operates a relief valve which cuts off normal supply going to coursening [sic] oil pressure and allows feathering oil to follow same path as normal coursening [sic] oil to rear of

[page break]

piston, thrusting the piston to its most forward position. On the completion of feathering action a pressure operated switch cuts out the aux pump. Oil from front of piston escapes to sump via C.R.V.

Note:- During the above 3 operations the distributer valve is stationary.

[underlined] Unfeathering [/underlined]:- Hold feathering switch in to prevent tripping at 400 lbs[symbol]" pressure then builds up to 500 lbs[symbol]" overcoming the resistance of spring retaining distributer valve which taking up a fresh position allows the H.P. oil to go through normal oil press. passage to front of piston.

Oil from rear of piston escapes to sump by C.R.V. at a predetermined time DUMP HOLES in piston sleeve line up with dump port in distributer valve allowing press to return to sump by C.R.C.

[underlined] Feathering [/underlined] Ground checks:-
1/ Engine oil temp normal.
2/ Batteries fully charged.
3/ Throttle 1500 R.P.M.
4/ Press. feathering button which will remain in releasing itself at fully fine position

[underlined] Unfeathering [/underlined]:-
1/ Allow prop to remain feathered only a few secs. (10)
2/ Press button and hold in
3/ Release button when R.P.M. is approx 1000
4/ R.P.M. will then return to 1500.

[underlined] Dash pots [/underlined] to act as a cushioning effect after feathering.

[underlined] Dump holes. [/underlined]

[page break]

[underlined] Unit Maintenance Orders [/underlined]
[underlined] Pt. I [/underlined] These orders are issued by the station commander and describe the unit maintenance organisations to co-ordinate the teckical [sic] work on the station.

[underlined] Pt. II [/underlined] Are issued for the guidance of squadron commanders by the commanding officer concerned (i.e. Bomber Com.) and are based on the appropiate [sic] maintenance schedule.

(Vol II pt II Issue No.1) issued by A.M. for each type of A/C. These may be amended or supplemented to suit commands requirements

[underlined] K.R's & A.C.I's [/underlined]
Chapter II Regulations relating to maintenance, inspect. and testing of A/C.
Chapter XII Regulations relating to flying.

[underlined] Maintenance Schedule [/underlined]:-
Part I Between flights and Daily inspections
Part II Minor & Magar [sic] inspections

Between Flt. Inspections:-
Only oil, fuel, and coolant to be signed for.

Daily Inspections:-
Form 700 A/C Serviceablity [sic] Certificate
1/ Cover contains instructions for use. Front of cover contains No. of A/C., Date of commencement F.700, Unit, Inspect. Period.
2/ (1) First Page:- Top. R.H. Corner serial No. of F.700, Type of A/C, Type of engines, fuel, oil, coolant, hydraulic oils.
(3)/ Period of minor inspections
(4)/ When next inspections are due
(5)/ Serial nos. of engines, or replacement and when installed

3/ Concerns daily inspection status Appr. columns signed by airman concerned. Last volume signed by N.C.O. i/c Flt.

[page break]

4/ State of fuel. Signed by airman concerned. Signed in last column by pilot.
5/ Statement of oil, coolant, and armament. Signed by Airman & pilot.
6/ Change of servicablity [sic] and log. Left hand page puts A/C. U/S.
7/ Flying times and pilots initials
8/ Maintenance Schedule Pt. II
(1) Airframes c.o. A/C cockpit
(2) Engines P.P. Power plant
(3) Instruments F.U. Fuselage
(4) Electrical PROP. Props.
(5) Wireless U/C Undercarraige [sic]
(6) Arm



Form 700 A. Travelling Copy:- Carried when A/C is on detachment. Must show flying hours up to time of leaving unit. On return details copies into F.700. Form 700A to be kept until inspections have been repeated at parent unit.

[page break]

FORM 171 Report upon damage to property caused by forced landing

Airframe:- Vol I Discriptive [sic] hand book and pilots notes
Vol II Pt I General orders and mods.
Pt 2 Maintenance schedules.
Pt 3 Instruction for repair
Vol III Pt 1 Schedule for spare parts.
II Apendix "A"
III Wt. sheet summery. [sic]

Engine:- Vol. I Descriptive hand book.
Vol. II Pt I General orders and mods.
II Fits and clearances.
III Instruction of overhaul
Vol. III Schedule of spare parts.

Aircraft on Detachment:- Publication carried
Vol I Vol II Pt 3.

Engine Vol 1
U.M.O's Pt 2
F7OOA F171
A.P. 1464 R.A.F. Engineering manual
Vol 1. Pt(a) General Engineering principles sub-divides.
Pt I General index.
Pt III General engineering ([indecipherable word] etc.)
Pt IV Aeroengines – over haul, etc.
Pt V Airframes – over haul, etc.

Vol. 1 Pt (B) Deels [sic] with use of construction and repair.
Vol. II Consists of mis. [indecipherable word]
III Ground equip. spares

A.P. 1181 Starting system of engines
Safety Equip
1441 Cold weather precautions

[page break]

1275 Instruments.
1095 Electrics
1538 Props
1374 Ignitions
1519 Air Pumps.
957 Fire Manual.
958 Basic of all [indecipherable word]
1574 A/C publications
113 Publications and leaflets

Class I Mods to safety to personnel.
Pts. sent direct from A/M.
A/C grounded untill [sic] mods embodied
Class II [indecipherable word] for full operational use of A/C.
Parts ordered imediatly [sic]. Embodied at Station
commanders descreosion [sic]
Class III (a) Simple mods. requiring min. amount of work
(b) not requiring supply of parts.
Class IV Embodied by makers only, unless otherwise notified

A/C ___ PILOT ___ F/E ___
03.25 HRS. P.O radiator temp up 105°c.
oil temp. Normal 55°c
oil press. 85lbs[symbol]"
03.35 P.O. radiator temp up to 125°c
oil temp normal
oil pressure normal.
Exhaust flame has slight suspicion [sic] of yellowness.
Engine throttled back to -2lbs Boost.
Checked radiator flaps open.
03.55. P.O. radiator temp down to 80°c.
oil temp 40°c.

[page break]

Opened up to normal cruising
04.10 P.O. rad. temp 180°
oil temp 50°
oil press 85° [sic]
Prop. feathered engine stopped

Suspect internal coolant leak.
Signed [signature]



[page break]

Entry 106

[underlined] TYPE [/underlined]

[page break]

[underlined] LAY-OUT OF "LANCASTER" [/underlined]


[page break]


Lancaster is a [sic] all metal heavy bomber. The fuselage is of semi-monorque construction divided into 4 fuselage sections and 1 centre section. The fuselage has 52 formers lettered K to A including I and numbered 1 to 41. Transport joints which accour [sic] at forms E,6,12,27 being specially reinforced and connected by high tensile steel bolts (H.T.S.B.) Stringers which run longditudinally [sic] are continues[sic] between transport joints. Main plane consists of a centre section and 2 outer wings of detachable wing tips

[underlined] Emergency Exits [/underlined]
1/ [underlined] Parachute exit [/underlined]:- Situated in the floor of the bomb aimers compartment. To jettison pull ring, lift flap turn diagonally and drop outward.
2/ [underlined] Ditching exits [/underlined]:-
a/ In roof above pilot's head. }
b/ In roof of rest bed position. } Jettison turn handle clockwise and push outwards
c/ In roof just forward of mid turret }
3/ [underlined] Entrance and exit door [/underlined]:-
Situated on Starboard side may be used as a parachute exit in [underlined] extreme [/underlined] emerancy [sic]

Crash exits 1/ Situated Stbd side forward of F.E. Panel.
2/ Situated Stbd side opposite rest bed
3/ Situated Port side opposite entrance door.

[page break]
Image 51 page 1
[underlined] CONTROLS [/underlined]:-
[underlined] Rudders [/underlined] are operated by means of push and pull tubes supported in tufnel bearings running down the port side of fuselage, they are detachable at transport joints and have a squared section aft of rear spar and at the extremity of push pull tubes (to resist torque) Forward end of push pull tube is connected to Port pedal by means of transverse rod. And ancillary rod is connected to squared section by means of a lug attached by a bolt. The after end of the auxillary [sic] rod which runs through the centre of the tail plain [sic] attached to a bell crank lever. From the B.C. lever push pull tubes run to the port & stbd rudder.

[underlined] Elevators [/underlined] are operated by push pull tubes as above to squared section. The forward end of P.P. tube is connected to a lever integral with a cross shaft to the bottom of the control column. An auxillary [sic] connected by means of a lug to the squared section of p.p. tube is attached at the after end of aux. rod, to a lever integral with elevator spar

[underlined] Ailerons [/underlined] are operated by means of sprockets, chains, tie rods and cables. The control wheel is connected to a layshaft running beneath the pilots floor by means of sprockets, chain cables giving a rotation on the layshaft by rotating control wheel. The rear sprocket on the layshaft is connected to two horizontal sprockets on the port side having two turning links on the chain, termination of chain is attached to two tie rods running down the port side of fuselage as far as front spar. The [deleted number] 45 cwt cable attached to tie rods from front spar to rear spar terminating to two chains attached to two horizontal sprockets on rear of rear spar. Tie rods from the chains connect to the top and bottom of a centraly [sic]

[page break]

mounted rocker lever attach to rear of rear spar. Push pull tubes attached to top of rocking lever beneath tie rod connect run out to Pt & Stbd. ailerons respectively.

[underlined] Damage to Controls:- [/underlined]
Rudders & Elevators
1/ Assist pilot
2/ Operate trimming tabs.
3/ Assatain [sic] damage, if tube is splintered, remove splinter. If movement not sufficient remove tufnel bearing from former. As a last resorse [sic] disconnect auxillary rod from squared portion of p.p. tube.
4/ Operate on trimming tab for further movement after disconnection

[underlined]Damage to Ailerons [/underlined]:-
1/ Assist pilot
2/ Operate trimming tab.
3/ Assatain [sic] damage – disconnect p.p. tubes from rocking lever. If rocker lever free to rock no damage forward of rear spar. Test p.p. tubes for movement, if no movement on one connect up undamaged p.p. tube to rocker lever and work on one aileron. Secure damaged p.p. away from lever.

[page break]



Icing conditions occour [sic] in temp of [underlined] +4°c to -12°c. [/underlined] and in [underlined] clouds [/underlined] Critical 0°c to -7°c.
check:- 1/ Contents of tank
2/ Turn master cock on.
3/ Open needle valve on B/A pump, and release stirrup catch and depress plunger few times.
4/ Fluid should issue from perforations on B/A window
5/ Similar action on pilots pump, fluid from twin nozzle
Recommended setting:-
Set needle valve to 1 2/3, with one pump per. min. on each pump fluid will be used at rate of 1 pint per. hr. on each pump.

[underlined] DINGHIES & DITCHING [/underlined]:-
[underlined] TYPE "Q" [/underlined] This is a sailing dingy [sic] inflated with CO2 to a pressure of 1 1/2 lbs. It has a bouyoncy [sic] factor of 3000 lbs and is capable of holding 7 to 9 persons. The bouyoncy [sic] tube is devided [sic] into 2 by internal baffles. fitted amidships where an inflatable [indecipherable word] tube ensures lateral rigidity. This [indecipherable word] tube has to be inflated seperately [sic] by connecting a hand bellows to the special rubber inflation valve. A canvas keel attached to bottom of dingy [sic] is extended by the insertion of the lower portion of the telescopic mast

[page break]

and is further braced by fore and aft cables which are tentioned [sic] when the mast rigging lines are tight.

At the stern attachment fittings are provided for the canvas rudder.

[underlined] STOWAGE:- [/underlined] Stbd centre section aft of rear spar.

[underlined] RELEASES:- [/underlined] 1/ Electrical:- by means of an electrical circuit completed when water entres [sic] the 2 immersion switchs [sic] situated in Pt & Stbd side of B/A. Comp.
2/ Manual:- by means of a cable carried in a red conduit tube passing along the roof of stbd side operated from 3 positions inside A/C.
a) Operate flap jack
b) Rear ditching exit
c) Enterance [sic] and exit door.
External - Stbd side, forward of tail plane.

[underlined] EQUIPMENT IN DINGY:- [/underlined]
1. [underlined] CO2 Cylinder [/underlined]. Fitted on Stbd side and contains 7 lbs. On release gas is passed via a short high pressure tube to twin inflation valves, feeding the seperate bouyancy chambers.
2/ [underlined] Operating Head. Type "H" [/underlined]. Set when green spot is visible through persex [sic] panel in stowage cover.
3/ [underlined] Topping up valves. [/underlined] Fitted on pt. side of bouyancy tube on iether [sic] side of central thrust[?]. Incorperates [sic] a relief valves which blow off at a pressure 1 3/4 lbs[symbol]"
4/ [underlined] Leak stoppers or repair outfit. [/underlined] Stored on bouyancy tube. Stbd side in bow.
5/ [underlined] Rescue line [/underlined] and quart, Pt side of bow
6/ [underlined] Floating Knife [/underlined] on top of bouyancy tube near CO2 cyl
7/ [underlined] Glove paddles [/underlined] attacked [sic] by lanyard to hauling in lines.
8/ [underlined] Hauling in line [/underlined] lies across dingy with single rung ladder pt. side.

[page break]

9/ [underlined] Drogue and attachment line [/underlined]:- In pocket on floor at stern.
10/ [underlined] Maps [/underlined] – A set of 18 maps – 1 Nav. chart – one instructional booklet in pocket at stern.
11 [underlined] Compass [/underlined] – in pocket beside map stowage.
12/ Weather cover – in 3 sections – fitted across bows and along either side of dingy. Coloured blue on under surface for camoflage [sic]

These bags are installed in the dingy stowage and contain 1/ Topping up bellows & fishing tackles.
2/ Telescopic mast and guy lines
Forward – yellow
Aft – brown
Pt. – red.
Stbd – green
3/ Sails and haulyards [sic] – main and foresail complete
4/ Canvas rudder.

[underlined] CONTENTS OF EMERGENCY PACKS. [/underlined] TYPE V (maker canvas type)
7 – tins Mark II Emerg. rations
10 – tins drinking water.
1 – cup
1 – 1" Signal pistol.
10 – tins of signal cartridges – 3 per tin.
1 – F.A. Outfit
1 – [deleted] Falaur [/deleted] Flouracent [sic] marker.
1 – tin matchs [sic]
1 – Distress flag
1 – 4" heliograph
1 – Spong [sic]
1 – Ariel [sic] loading coil.
This pack is attached to floor of dingy.

[page break]

TYPE No 7.(Valise type)
18 tins drinking water
18 tins signal cartridges – 3 per tin
2 Floracene [sic] sea markers
This is stores [sic] Stbd. side – aft of rear spar. Dingy radio set and 2 kite ariels [sic] are stored on pt. side above rest bed.

[underlined] TYPE "K" [/underlined] – This is ONE man dingy to each member of crew. The dingy pack attached usually to Mae West by means of quick release units. The dingy is inflated with CO2 to a pressure of 1/2 to 3/4" lbs[symbol]” and has a bouyancy factor of 320 lbs. The CO2 is contained in a cyl having a gas charge of 12 ozs. and is released by removing locking pin from the operating head and unscrewing
N.B. It is important that the operating head is unscrewed [underlined] slowly [/underlined] as otherwise serious damage may occur to dingy.

[underlined] EQUIPMENT ON DINGY:- [/underlined]
1/ Topping up bellows.
2/ Topping up value.
3/ CO2 cyl.
4/ Baler.
5/ Drogue.
6/ [indecipherable word] Pockets.
7/ Water pockets and trip line.
8/ Weather apron and hood.

[underlined] CONTENTS OF SPECIAL PACK: [/underlined]
1/ Rations
2/ Compass.
3/ Distress signals
4/ Leak stoppers
5/ Sail and mast.
6/ [indecipherable word] paddles.
7/ Heliograph.

[page break]

Prior to ditching:- On receiving "Dingy, Dingy, prepare for ditching" and call light "D", "D", "D" you should take following action.
1/ Say "Engineer ditching."
2/ Remove parachute harness.
3/ Assist pilot as required.
a) Fuel jettison.
b) Release pilots harness
c) Fasten Sutton Safety Harness
4/ Jettison hatches.
5/ Collect axe and move aft to ditching station
6/ Remove collar and tie if warned [sic].
7/ Retain helmet if possible (for protection)
8/ Inflate Mae West (To suit build)
9/ Take up position on your back on rest bed and connect intercom. with pilot. Secure safety belt across your chest, place right hand on release catch and protect your face with left arm pressing your head on back rest, brace your feet against bulk head keeps [sic] knees well flexed. Left foot to port side and right towards hinge. [deleted letter]
10/ On recieving [sic] order from pilot shout "Brace for ditching" and disconnect intercom.
11/ Brace yourself for impact maintaining your ditching position until the [underlined] second [/underlined] impact have been felt and A/C has come to rest.

[underlined] AFTER DITCHING:- [/underlined] 1/ Take axe leave first from mid ditching exit and assist dingy out of stowage.
2/ Get dingy water born with aid of the navigator
3/ Control dingy Together from wing
4/ Take up position in dingy when all crew, except pilot, are aboard.

[page break]

[background page appears later]

[inserted] Single-Seater

THE R.A.F. has always been provided with first-class safety equipment to enable aircrews to meet any contingency which might arise during flight, but it was not until this war really began that emergency dinghy gear was regarded as an essential part of equipment, and even then, in the early days, it was not imagined that the severest fighting in the air would take place over the sea. It is for this reason that the dinghy is now looked upon as just as important an item of equipment as the parachute, and in fact it is probable that many aircrews are flying now who would have been prisoners in enemy hands had they not had full confidence in taking to their emergency dinghy in the North Sea rather than jumping by parachute over enemy territory before they reached the sea, which they knew they could not cross with their shot-up aircraft.

[italics] From the sketch by Charles A. Robertson, Founder & Hon. Secretary, Goldfish Club [/italics]

The average man is very apt to imagine anyone but himself in a certain predicament, so great pains are taken to instruct aircrews in the correct method of operating a dinghy in an emergency. It is, of course, difficult to simulate the real conditions which occur when an aircraft makes a forced landing in the sea, but aircrews who have had to use a dinghy in an emergency are often thankful for the apparently boring practices which they previously had to make, time and again. The success of emergency dinghies depends to a large extent on the knowledge of the user, and, in multi-seat dinghies, one member of the crew may prove to be the weak link in what would otherwise have been a completely successful “ditching.”

The K Type
The single-seater dinghy, or K type, as it is generally called, is designed for use either in single-seater fighters or in larger aircraft where it is not practicable to have one large dinghy for all the crew.


In the latter cast each member of the crew has a K type of his own. This dinghy is the only type which is actually attached to the user when in the aircraft; the reason for this arrangement is so that the wearer may abandon the aircraft in mid-air, come down by parachute and land in the sea complete with his dinghy, since small aircraft such as single-seat fighters are rather difficult to land on the water, and, moreover, they do not usually float as long as a bomber. If the pilot of a fighter landed his aircraft on water he would have to be strapped in to prevent himself from being thrown forward when he touched the water, and he might not have sufficient time to free himself from the harness before his aircraft sank.

There are several different arrangements for the K-type dinghy, but perhaps the most usual is the seat type. This one is used when the pilot is equipped with the kind of parachute pack which hangs down behind him and upon which he actually sits in the aircraft. The dinghy, which folds up into a pack roughly about the same shape as the parachute pack, but not so thick, clips on to the latter, and is positioned between the parachute pack and the wearer, so that, when in the aircraft, he is sitting on a cushion consisting of the parachute and the dinghy both folded away in their respective packs. There is a piece of webbing which attaches the wearer to the folded dinghy in the pack, and the webbing is connected by a quick-release attachment to some part of the pilot’s clothing or equipment.

First Stage
When, in an emergency, the pilot has to jump from his aircraft over the sea, he opens his parachute in the normal way as soon as he has fallen clear of the aircraft and floats down to the sea. On touching the water he operates his parachute harness quick-release unit, which immediately frees him from the parachute and harness and leaves him with his dinghy pack in the water beside him. It does not take long to get the dinghy working, but the pilot may be wearing boots
CONTINUED ON PAGE 8 [/inserted]

[page break]

[background page appears earlier]
[inserted] Single-Seater


and heavy clothing, and he will blow up his “Mae West” as soon as he gets in the water; this will keep him safely afloat while he gets the dinghy pack open.

The pack is easily opened by pulling on the handles provided at each side of it. A cylinder of compressed carbon dioxide is at once exposed which will inflate the dinghy as soon as the former and the folded dinghy are pulled out of the pack and the valve on the cylinder slowly opened. If it were opened too quickly the sudden rush of gas might burst the dinghy. The pilot then climbs into the dinghy in such a way that he does not upset it, and sits himself down in comparative comfort, still attached to the dinghy by the piece of webbing, so that if he should happen to fall overboard the dinghy will not float away. The rest of the dinghy pack is attached to the dinghy by a piece of cord, and when this is hauled in the pilot will find a lot of useful articles packed away. Amongst them may be emergency rations, distress signals, a drogue to prevent the wind blowing the dinghy too fast across the water, and leak stoppers for plugging any holes which may have appeared in the fabric of the dinghy. Stowed in the dinghy itself there will be topping-up bellows and a baler. There are obviously few situations which could arise for which the pilot could not find a remedy amongst his equipment. Some of the K-type dinghies have got waterproof aprons with which the pilot can completely cover himself except for his head and arms, which stick out of holes in the apron; others have a mast and sail, and in skilful hands these little dinghies have been known to make voyages which many seamen would never risk in a boat four times its size.

It Needs Practice
Having read this brief description of the working of the K-type dinghy, it may appear that the whole thing is delightfully simple, and that providing the pilot keeps his wits about him and does the right thing at the right time he cannot go wrong. But what must be remembered is that the whole thing happens in an extremely short space of time; the pilot may have just been in contact with the enemy, there may be a big sea running, it may be a bitter January day; and unless the pilot knows subconsciously what to do and when to do it – which knowledge he can gain only through practice of his dinghy drill – his chances of a successful ditching are greatly decreased.

Back to the Fold
By Philip Banbury

WINGS that would fold were standard up to 1940 on many aircraft for private use and civilian training and on all shipborne aircraft. Since then the only aeroplanes built with folding wings have been those in the latter category, though the Seafire, Sea Hurricane and Zero fighters and the big twin-motor Mitchell bombers have been used with fixed wings. The problem presents certain difficulties other than those connected with the mere mechanical accomplishments of the folding, which may partially or completely nullify the obviously great advantages.


The sketches show the methods in common use. The method employed on biplanes is simple from the manufacturing point of view, and the folding is easily carried out even on a large machine.

Method A.

It was used also for folding the outer wing panels of the de Havilland twin-motor Dragon transport.

Method B.

Monoplane (method A) is the scheme used on most British carrier-borne monoplanes and on some private-owned types. The wing illustrated hinges, leading edge downwards, the top surface being outwards; a variant is trailing edge downwards and under-surface of wing outwards. On a two-spar wing the hinge may be on either spar or on a jury spar between them. Whichever variant is used there is no need for hinged flaps on the trailing edge, as in method C.

Monoplane (method B) may be loosely labelled the American method, since it is usual on U.S. shipborne aircraft. Once again hinged trailing-edge flaps are unnecessary. This is the simplest method of all, though it does not permit quite such a reduction in dimensions as does method A, since the smaller the span the greater the height.

Method C is the way it was done on light single-motor civil aeroplanes, both high and low wing. The wing hinges on the rear spar after a flap (shown folded in the starboard wing and dotted in the port wing) has been lifted. The aerodynamic flaps were usually fitted in the lower surface of the folding flap, and after being disconnected were lifted up with it. This method of folding was used with variations on Percival, de Havilland and Miles civil aeroplanes.

There are other methods, of which the most notable was that evolved by Mr. Baynes for the little twin-motor private-owned aeroplane be designed. In this machine the whole wing, which was in one piece and mounted on the top of the fuselage, complete with

Method C.

8 [/inserted]

[page break]

A 3 pint Grovener [sic] fire extinguisher containing Methal Bromide is mounted on the rear face of front spar of the 2 inboard engines and on the bulkheads behind the outboard engines. When the extinguishers are operated the methal bromide is sprayed on in the form of a gas arround [sic] the sparking plugs, and into the chokes of carb. This gas has a smoothing and cooling effect on the fire but has no detrimental effect on the engine itself.

The extinguishers may be operated by any of the following
1/ [underlined] Push button [/underlined]. Stbd side of pilots panel.
2/ [underlined] Inertia switch [/underlined] – Stbd side B/A Compartment, operates at 6G.
3/ [underlined] Gravity [/underlined] - Stbd side B/A. Compartment – operates extinguisher for all engines if A/C turns over on its back, but only when U/C is fully [underlined] locked down. [/underlined]

[underlined] Fire in an engine:- [/underlined]
1/ Captain warns crew
2/ Orders pilot and F.E. to carry out feathering drill on engine.
3/ When engine has stopped, and [underlined] not [/underlined] before, and fire has [inserted] Mastecock [sic] off [/inserted] not gone out, F.E. will operate push button.
5/ If on inboard engines, turn off cabin heating

[underlined] Action in event of fire in fuselage:- [/underlined]
1/ Close all doors and windows, cabin heating etc.
2/ Warn crew to wear oxygen masks. Emergency setting.
3/ Attack fire working in relays.
4/ When fire is extinguished open windows to clear A/C of all fumes.

[underlined] Portable fire extinguishers:- [/underlined]
1/ B./A. Comp. Mk I Port side Mk III Hand rail Stbd (2 pint[?]) Controlable [sic]
2/ Port side pilot's seat. (1 pint) Controlable [sic]
3/ Front face nav. table (1 pint) Controlable
4/ Top front spar – Stbd side (2 pint) plunger type.
5/ aft mid turret Stbd side (1 pint) Controlable
6./Forward rear turret Port side (1 pint) Controlable

[page break]

[underlined] OXYGEN SYSTEM [/underlined]:-


[underlined] OXYGEN BOTTLES [/underlined] stored beneath rest bed. 3 banks of 5. Bound with wire to prevent fragmentation and supplied with none-return valves to avoid loss of oxygen.
[underlined] MAIN SUPPLY COCK [/underlined] situated of forward face of rest bed
[underlined] PRESSURE REGULATOR [/underlined]. situated on Stbd. of pilots panel, acts as a pressure reducing valve. (Contents gauge with master cock below, and flow meter and flow regulator below)
[underlined] MANIFOLDS [/underlined] – 4 in number. (2 B/A Comp. Stbd side – 1 by Oxygen Pt. 1 – Former 22 by flare chute Pt side front face.)
[underlined] ECONOMISERS [/underlined] at all crew positions, also at rest bed

[page break]

flare chute, elsan. (No economisers in Mk I turrets) (9-in Mk I 12-in Mk III)

[underlined] FLOW INDICATOR [/underlined] and [underlined] CUT OFF VALVE [/underlined] assemble to all economisers. (Pilot no flow indicator & cut off valve. – F.E. no flow indicator)

High pressure oxygen at 1800 lbs[symbol]" pressure is convayed [sic] to pressure regulator via a main supply valve. Pressure Reg. reduces pressure to the manifolds, from the manifolds low pressure oxygen is convayed [sic] to each economiser.

[underlined] Oxygen Used [/underlined]:- 1/ Over 15,000 ft
2/ Over 10,000 ft when duration is over 1 hour
3/ Over 20,000 ft in cold weather.
4/ From 4,000 ft when flying at night.
5/ When rate of climb exceed 2000 ft. per. min.
6/ Fire inside fuselage.

[underlined] Flow Meter Settings [/underlined]:-
1/ From take off set at 15000 ft.
2/ At 15000 ft reset to 25000 ft.
* 3/ All altitudes above [underlined] 20,000 [/underlined] ft flow meter must read [underlined] 5,000 [/underlined] above true altitude

[underlined] Checks [/underlined]:- 1/ Turn on main supply valve.
2/ Turn on master cock and ensure gauge reads "FULL"
3/ Turn on flow regulator until flow meter reads max. supply then reset to 30,000 ft.
4/ At each economiser ensure flow indicator reads "OFF" with bayonet union of flexable [sic] hose in cut off valve clip
5/ Remove bayonet union, flow indicator should read "ON"
6/ Hold bayonet union of flex hose against face 5 - 9 puffs should be felt per. min.

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[underlined] FEUL [sic] SYSTEM [/underlined]


[page break]

[underlined] NITROGEN SYSTEM [/underlined]:-


[underlined] Fuel System [/underlined]:-
Components – [underlined] Tank Selector Cocks [/underlined] – situated on F/E Panel for changing from No 1 to 2 or 2 to 1 also for running from one tank only.

[underlined] Pilots Master Fuel Cocks [/underlined] – situated on either side of throttle quadrant. Allows fuel to all engines. "ON" position "UP".

[underlined] Cross Balance Cock [/underlined] – situated on front face of front spar. in centre of fuselage. Only "ON" when running 4 engines from 1 tank

[underlined] Selector cock [/underlined] – front face of front spar inboard of inbd. engine and is remotely controlled by T.S.C.

[underlined] Inboard Master Cock [/underlined] – Incorperated [sic] with selector cock and controlled from Pilots master fuel cock lever.

[underlined] Outboard Master Cock [/underlined] – on front face of front spar just inbd. of inbd. engine and is controlled from Pilots master fuel cock.

[underlined] "Ground" to "Flight" Switch [/underlined] – Stbd. side, aft of front spar

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Priming:- a Ki-Gass pump is situated on U/C Aux. panels Stop cocks are provided so that each engine can be primed independantly [sic]. Also situated on Aux panels.

[underlined] Ammeter test on Fuel Booster Pumps [/underlined] – If ammeter not fitted plug in ammeter to socket on F/E panel. With boost pump switchs [sic] on "Test" one at a time. Readings as follows:-
Immersion pumps – 2 to 4 Amps.
Pulsometer pumps – 4 to 7 Amps
[underlined] Note [/underlined]:- “Ground” to “Flight” switch on "Flight" position

[underlined] Fuel Boost Pumps used as follows [/underlined]:-
a) Take off – 4 pump in case of emergency
b) Over target – 4 pump in case of emergency
c) Landing – 4 pump in case of emergency
d) Over 17,000 ft – 2 pumps for tanks in use as pressure or air in tank has been reduced

[underlined] Fuel Proceeder [sic] for Starting [/underlined] :- Take off & Normal Flight:
1/ Check balance cock "OFF"
2/ Switch on fuel contents gauge, leave on for all flight
3/ Check fuel state.
4/ Test all booster pumps (Ammeter)
5/ Switch on booster pumps for No. 2 tanks.
6/ Start up , run up, warm up on No. 2.
7/ During run up switch "off" booster pump to test gravity
8/ Change to No. 1 check booster pump
[inserted] Take off [/inserted] 9/ Take "off" on No. 2 with No. 2 + 1 booster pumps running.
10/ If warning lights should come on during take off warn pilot and change to No. 1. After initial climb and level out, change back to No. 2 tanks, and if lights come "On" a second time reselect to No. 1 tanks and land as convenient
11/ Take off O.K. booster pumps "off"
12/ Run off No. 2 tanks for 1 hr 20 min.
13/ Select No. 1 tank and switch on No. 3 booster pump.
14/ Switch off No. 3 booster pumps before tank is completely empty.

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13/ Continue to run off No. 1 tanks until fuel of No. 1 & 2 are equal
14/ Select and run from No. 2 tanks for 1 hour.
15/ Select and run from No. 1 tanks for 1 hour.
16/ Continue for 1 hour intervals alternately from 1 & 2
17/ Leave 100 gals in No. 2 and drain No. 1
18/ Always warn pilot when according to fuel log 1 hours fuel remains, and again when reduced 1/2 hour
* Do not rely on fuel gauges.

The nitrogen system provided for introduction of nitrogen into fuel tanks as the fuel level is lowered in order to minimise the risk of fire. It is stored in oxygen type bottles painted grey with a black band, 7 bottles on forward face of rear spar and 5 on Stbd side. Nitrogen is fed at 1800 lbs[symbol]" pressure from the bottles A control cock and pressure gauge situated on Stbd. side above the bottles controls the flow and pressure. The nitrogen is then led [sic] through a filter and "Palmer" reducing valve, reducing pressure to 15 to 25 lbs[symbol]" the pressure is further reduced by means of an Amal valve to .25 lbs/[symbol] The filter, reducing valve & Amal valve are situated on the rear face of front spar in Stbd & Pt U/C [indecipherable word].

In order normally to exclude air from tanks (except if nitrogen supply fails to make up volume of fuel used) and to prevent the loss of nitrogen a double acting vent or Snifter valve set to 0.25 lbs[symbol]" and operating in both directions is fitted in each tank vent pipe. Control cock should be turned on before flight and left on throughout the flight, pressure gauge should be checked 1/2 hour after take off to ensure pressure has not dropped by more than 200 lbs[symbol]". External charging valve, Stbd side bomb bay skirt.

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[underlined] FUEL JETTISON [/underlined]:-
Fuel can be jettisoned from No. 1 tanks from any amount down to 80-100 gals. Jettison is hydraulical [sic] operated and controlled by selector on left hand side of pilots seat. Selector painted red and operated by raising and turning anticlockwise.

[underlined] Action before jettison [/underlined]:-
1/ Warn rear gunner.
2/ I.A.S. 115 – 150 M.P.H.
3/ Lower flaps 15° – 20°
4/ Stand by with extinguishers.
* [underlined] Never [/underlined] jettison if there is any trace of fire.

[underlined] WHEN TO USE EMERGANCY [sic] AIR IN HYDRAULIC SYSTEM:- [/underlined]
If U/C fails to come down fully the F/E must decide what what [sic] is causing the failure and what means he has to over come this failure and the following pointers will guide him.
1/ The most important is the time at his disposal which is governed by state of aircraft, i.e. damage by enemy action, state of petrol, etc. The factors deside [sic] weither [sic] he will without hesitation lower his U/C by Emergency Air
2/ If however time is not a vital factor he will ascatain [sic] by his accumulator pressure weither [sic] the failure is caused by E.D.P’s not delivering hydraulic pressure. If this is so the hand pump can be used upon which the U/C should start moving or the pressure in the accumalator [sic] gauge should built up until the auto. cut out byepasses [sic]. If in the case of this failing the F/E will resort to the Emergency Air, which with the extra kick of 1200 lbs pressure has been almost without exception effective in locking U/C.

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[underlined] ELECTRICS & INSTRUMENTS [/underlined]:- CPL. PEPPIN
[underlined] ELECTRICS [/underlined]:-


[underlined] Fusing [/underlined] –
H.E. bomb fusing is controlled from B/A position by 2 switchs [sic] marked “NOSE & TAIL FUSING” – “SAFE & FUSED" These switchs have to be selected to the "FUSED" position when H.E. are being released live. Incendaries are not controlled from H.E. fusing switchs as the fusing takes place automatically as the incendaries are released from the containers. To release and incendory [sic] unfused they have to be released by dropping the container intact.

[underlined] Safe Jettison of a mixed bomb load [/underlined] –
1/ Check bomb doors "Open"
2/ Push contain jettison switch
3/ Pull H.E. jettison handle.

[underlined] Live jettison of a Mixed Bomb Load [/underlined] –
1/ Bomb doors "Open"
2/ Select "NOSE & TAIL" fusing switchs [sic] to "FUSED"
3/ Pull H.E. jettison handle.
Mod. – The new bomb selector switchbox has a push button control for jettison in place of the origonal [sic] jettison bars In this case a push button also replaces the jettison handle on the copilots panel.

[underlined] Manual jettison [/underlined]
Open cover, remove fire pin plug, unscrew release unit, and pull back catch

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[underlined] SWITCH POSITION FOR EXTERNAL LIGHTS. [/underlined]

(a) NAVIGATION (b) Small panel. Pt side of pilot. (c) Select "ON"

(a) FORMATION. (b) 1/ To select colour. Main fuse panel (Stbd forward front spar) (c) Select required colour (b) 2/ Switch box. Main instrument panel below blind flying panel) (c) Select left lever to "Morse" or "Steady"

(a) Downward Identification (b) 1/ Select colour from 3 switchs beneath B.F.P. (c) Select required colour (b) 2/ Switch box. Stbd side of main instr. panel. (c) Select left lever to "Morse" or "Steady"

(a) Upward. (b) Switch box. Stbd side (c) Select right lever to "Morse" or "Steady"

(a) Head light. (b) 1/ Select "Independant" or "Signalling" on main fuse panel (c) Select "Indep" or "Sig". (b) For "Signalling" use switchbox Pt. hand side Main Instr. Panel (c) To signal left hand lever to "Morse"

[underlined] Generator and Battery Circuits [/underlined]
[underlined] BATTERIES:- [/underlined]
Capacity of 80 A.H. at 24v is obtained from 4 – 12v – 40 A.H. Batteries connected in Series – Parallel. They are kept charged during flight from the A/C. Generators but will assist the generators when circuit loads are required which exceed the generator output (120 amps) The batteries also provide an emergency supply in the event of generators failing.

[underlined] BATTERY TEST [/underlined] – Turn "Ground to Flight" switch to "Flight"

[page break]

switch on circuit load of 8 amps for a period of 5 min. checking that the voltmeter reading does not fall below 24.v. during test. The W/T. receiver is a suitable load for this test. The test must be done [deleted word] before generators have cut in. "Ground" to "Flight" switch, this the internal battery master switch "Flight" being "ON" and "Ground" is "OFF". The switch must be left in "Ground" position whenever A/C is parked so that the internal batteries are isolated. When using a trolley for starting the switch must again be at "Ground" but having started from the trolley the switch must then be turned to flight to maintain the supply to the various instruments from the A/C batteries.

[symbol] If the "G to F" is in the "Ground" position during flight the internal batteries will not be charging from the generators. The A/C circuits will run as normal from the generators unless a heavy load is switched on, in which case batteries are unable to assist the generators and the generator voltage would be reduced to a very low valve

The danger of having "G to F" switch in "Flight" with the trolley also plugged in is that the A/C batteries will probably discharge into the trolley. In some cases discharge may be sufficient to burn out the battery circuit wiring and cause a fire

[underlined] GENERATORS [/underlined]:-
Two – 29v – 60 Amp. generators (1500 watts eachs [sic]) are driven off the inboard engines, the two being coupled in parallel to give a total output of 29v – 120 amps. The generators cut in when there [sic] voltage rises to 27v. (approx 1400 R.P.M.) When Automatic cut outs close and completing the circuit between the generators and batteries. These cut-outs remain closed during flight, but will

[page break]

open when ever the generator voltage falls below the battery voltage, this prevents discharge back through the generators from the batteries. At approx 1600 R.P.M. the generator voltage will have risen to 29v at this point the Carbon Pile Voltage Regs. at [sic] brought into operation to maintain the voltage at 29v with any further rise of engine revs, the Current Regulator is fitted to each Voltage Reg. Unit to prevent the generator output being more than 60 Amps each. The action of the Current Reg. takes place when a load exceeding the gen. output is required. This heavy load causes the current regulators to reduce the gen. voltage to the same level as the batteries and the batteries then assist the generators with the heavy load.

[underlined] Battery, Voltmeter, and Generator Ammeters [/underlined]:- The battery voltmeter will read battery voltage when the "ground and flight" switch is to "flight" and the gener. not cut-in. Two generator ammeters will be reading zero. When the gen. cut-in the ammeters will show "Charge" the amount of charge depending on circuits in use. At the same time as the ammeters show charge the volt meter reading will rise to the generator voltage 29v

The effect of a damaged pair of batteries is to discharge the other servicable [sic] batteries and most likely reduce the generator voltage to a low value. To disconnect damaged batteries turn "G & F" switch to "Ground", remove the battery covers, disconnect the damaged accs, insulate disconnected leads check that the remaining pair are in series and return "G & F" switch to "Flight". As the batteries operate in pairs one being damaged will mean disconnecting a pair

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[underlined] INSTRUMENTS [/underlined]:- F/SGT. SMITH
[underlined] BLIND FLYING PANEL [/underlined]:-
1/ [underlined] Airspeed Indicator [/underlined] – Connected to pressure and static pipe lines, should this instrument be ZERO during flight examine. Divided into 5 M.P.H.
a) Pilot head switch [underlined] not [/underlined] "ON"
b) Pilot head fuse blown.
c) Pilot head cover left on.
d) Damage to pressure pipe line or instruments.

[underlined] Over reading [/underlined] –
d) Static pipe line damaged or glass.

[underlined] Under reading [/underlined] –
a) Leaky pressure pipe line
b) Or static vents blocked or pressure head.

[underlined] [missing letter]ate of Climb [/underlined] –
Connected to [underlined] static pipe line [/underlined]. Zero adjustment provided. If on a D.I. the pointer is not more than [missing word] or 200 ft. from Zero by turning bottom right screw

[underlined] [missing letters]ork X1V Altimeter. [/underlined]
Is an aneroid instrument connected to static pipe line.
D.I. – Obtain barometric pressure in millibars from met. office and set same on subsidiary scale Pointer should read to within + or - 50 ft of zero.

[missing word] one of the static instruments was damaged, [underlined] all [/underlined] would [missing word] effected, but where possible isolate the instrument [missing letters]cerned.

[underlined] [missing letters]flight check on Panel [/underlined]:-
[missing number]) Visual check (instru) (connections)
2) Test Anti-vibrational mountings
3) Obtain pressure, of day. (See above)
4) Cage & set direction indicator.
5) Adjust rate of climb is necc.

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BLIND FLYING PANEL – (Vacuum System) or (Suction)

1/ [underlined] Directional Indicator [/underlined] – (Gyroscopic)
Set to Zero for take off and landing (by caging and uncaging). During flight set to compass heading, check every [underlined] 15 minutes [/underlined] Enbles [sic] pilot to carry out accurate turn & used in conjunction with compass.

2/ [underlined] Artifical [sic] Horizon. [/underlined] – (Gyroscopic).
Indicates [deleted word] atitude of A/C relative to the horizon and number of degrees of roll. Stablised [sic] by an erection device. (10,000 to 12,000 RPM Gyro speed) Marked in 10° divisions

3/ [underlined] Turn and Bank [/underlined] – (Gyroscopic).
Indicates rate of turn of A/C in degrees per minute and degrees of side slip.
Bottom pointer attached to gyroscope, top pointer to pendulume [sic]. These instruments are driven by suction 4-6 inch mercury from P.1. Pesco Pump, while S.I. Pesco pump drives bomb sight. In the event of P.I. failer [sic] a change over cock is moved from "NORMAL" to "EMERGENCY" When the Stbd inner will drive the instrument panel, the bomb sight being U/S.
[symbol] If one of the gyro instr. was damaged the other two may be consided [sic] fairly reliable providing they did not include the turn and bank.

When underbanking in a turn the side slip points move opposite to turn pointer.
When overbanking it moves [inserted[ in [/inserted] same direction.

[page break]

Consist essentually [sic] of a master unit fitted Stbd of rear door, variation setting corrector (V.S.C.) fitted in Nav. roof and pilots and navs repeaters. Switchbox fitted port bottom of instru panel.

Proceedure [sic]:- Switch to "ON" and to "SETTING" after engines have been started, but before A/C moves. After 5 to 7 min switch to "NORMAL". Switch "OFF" after A/C has finally come to rest. In flight check assatain [sic] master unit reading Add or subtract "A" Error, inform navigator

[underlined] SIMPLE PRINCIPLE OF MK IV AUTO CONTROL [/underlined]

[page break]

[underlined] MK. IV AUTO CONTROLS [/underlined]

[page break]

TURN REGULATOR CIRCUIT:- To prevent elevator being applied during a turn.


[underlined] R.A.E. Compressor [/underlined] – fitted to rear of "B" bank pt, inner has 3 connections. Air Inlet, Oil Inlet, Air & Oil Outlet, [underlined] Oil reservoir and seperator [sic] [/underlined] – fitted Aux panel Pt inner, filled with anti-freezing oil to level of filler cap, also seperates [sic] air and oil.

[underlined] Chemical Air Drier No. 1. [/underlined] – fitted rear of pilots seat, contains 1 3/4 lbs of Silicon [sic] Gel obtainable in two colours
{White changes Brown} normal life 10 engine hours
{Blue changes Pink}

[underlined] Chemical Air Drier No 2 [/underlined] – fitted Pt. B/A. steps.
[underlined] Mk IV Units [/underlined] – Servo motors and Turn Regulator – fitted in Pt. B/A. position.

[underlined] Steering Control and B/Sight Cock [/underlined] – Pt. nose
[underlined] Main Control Cock [/underlined] }
Steering lever }
Main Switch } – fitted Pt. pilot
Atitude [sic] Control }
Clutch lever }

[underlined] Test Cock [/underlined] behind pilots seat

[underlined] Air throttle [/underlined] – pt inner bulkhead.

[page break]

[underlined] DAILY INSPECTION [/underlined]:-
1/ Top up oil reservoir with Grade "A" ANTI-FREEZING OIL to level of filler plug.
2/ Replemish [swic] Chemical air driers by reference to F.700
3/ See that covers are secure on units and turn regulator. Put M.C.C. "OUT". Steering lever "CENTRAL" Atitude control "O" Main switch "OFF" clutchs [sic] "IN"
N.B. To engage clutchs [sic] move lever to in position and operate controls over the full range until clicks are heard are [sic] added resistance felt.
4/ Run up P.I to approx 1800 RPM – Note pressure – put M.C.C. to "SPIN" (5 to 7 mins) Note press. again – put "IN" & check pressure [inserted] 60 lbs[symbol]” + - 5 lbs [/inserted]again, and see that controls are locked with stick slightly forward. Put M.C.C. "OUT"

[underlined] PROCEEDURE [/underlined]:-
[underlined] Take off [/underlined] – M.C.C. to "OUT" (all controls at zero)
After [underlined] Take off [/underlined] – M.C.C. to "SPIN" (5 to 7 min).
At 2,000 ft trim A/C to fly hands and feet off-cut "IN"
To turn A/C [underlined] switch "ON" [/underlined] – operate steering lever or control
Put steering lever central – [underlined] Switch "OFF" [/underlined]
[underlined] Evasive Action [/underlined] –
M.C.C. to "SPIN"

[underlined] Over target [/underlined] –
M.C.C. in "OUT" – B/Sight cock "ON"
To re-engage “George” put B/S cock "OFF”
M.C.C. "SPIN" (5 - 7 mins)
Trim A/C and cut to "IN"
Emergencies – Clutchs "OUT"
[underlined] Prior to landing [/underlined] – Put M.C.C. "OUT" Clutchs "Out".

[page break]


[underlined] External [/underlined].
1/ General aspect of A/C. (eg. Oleo leg extension)
2/ Chocks at wheels.
3/ Tyres for pressure, cuts, oil soakage, creep.
4/ Durey struts removed.
5/ Check for coolant leaks and any leakage from emergency air valves, oleo legs, and U/C jacks
6/ Inspect U/C latch cocks for cleanliness, and U/C member generally for damage.
7/ See covers are removed from:- Cable cutters, pitot head
8/ Check the hinged leading edges for securatity [sic], also all panels and cowlings.
9/ General check for damage to fins, rudders, elevators and tail plane.
10/ Examine fuselage for damage, remove plugs from static vents.
11/ Check the external First aid & Dingy release.
12/ See panels under fuel tanks are secure.
13/ Inspect tail wheel and oleo strap
14/ Check cock on bomb door emergency air is "OPEN"

[underlined] Internal – from rear to mid upper turret [/underlined]:-
1/ Remove [indecipherable word] from rear turret cut-off valve (oxygen)
2/ Check oxygen in bottle and fire extinguisher in front of the rear turret
3/ See that the dip sticks, F.A. Kit, Axe are safely stored.
4/ Check the portable oxygen bottle, fire extinguishers under the mid-turret.
5/ Remove [indecipherable word] from mid-upper turret cut-off valve

[underlined] From mid upper turret to front spar [/underlined]:-
1/ Check securaty [sic] of bomb slip covers
2/ Check the pyrotechnics for securaty. [sic]
3/ Securaty [sic] of rear ditching exit.

[page break]

4/ See that the oxygen bottle central locking gear, and axe are correctly stored.
5/ If nitrogen supply is fitted pressure should be 1800 lbs[symbol]" + or - 200 lbs[symbol]"
6/ Check mid ditching exit
7/ Turn oxygen supply cock on.
8/ Place "Ground to Flight" switch to "Flight"
9/ Check emergency air pressure 1200 lbs
10/ Secure step over the accumalators. [sic]
11/ Check hydraulic acc. 220 lbs[symbol]" (black oil)
12/ Check fluid in hydraulic reservoir for level with bomb doors open, ensure that filter is clean.
13/ See that the oxygen bottle and 2 pint fire extinguisher are correctly stored.

[underlined] From front spar to pilots panel [/underlined]:-
1/ Check Balance cock, leaving it in "OFF" position
2/ See that all negative isolation switchs [sic] are "ON"
3/ Check the oxygen bottle and fire extinguisher beside the navigator.
4/ Test the operation of U/C warning buzzer.
5/ Check pilots oxygen bottle.
6/ Check pilots fire extinguisher and axe.
7/ Test brakes and pheumatic [sic] system generally
8/ Check controls and trimmers for correct movement
9/ Check forward ditching exit.
10/ Check fuel contents and booster pumps. Master fuel cocks "Off". leave the fuel pressure warning switch on.

B/A Compartment
1/ Security of parachute exit
2/ Oxygen bottle and fire extinguisher.
3/ Remove [indecipherable word] from cut out valve front turret.

[page break]

[underlined] STARTING PROCEDURE [/underlined]:-
B 1/ Brake pressure 150 lbs[symbol]" minimum.
I 2/ I.C.O. switchs to closed position. (Merlin 28 Stromberg)
G 3/ "Ground to Flight" switch to "Ground".

B 4/ Boost cut-out lever up.
U 5/ U/C and flap indicators "ON"
S 6/ Supercharger to "M" Gear
T 7/ Throttle 3/4" open 1000-1200 revs

U 8/ U/C lever locked down, B/D's closes, Flaps neutral
P 9/ Props max. R.P.M. (fully forward)

A 10/ Air intake to "COLD", fuel jettison NORMAL.
M 11/ Master fuel cocks "OFF"

P 12/ Pumps on for No. 2 tanks. Select No. 2.
S 13/ Select Master cock for engine to be started
I 14/ Ignition booster coil "ON"

P 15/ Prime engine (Ground crew to prime till engine starts)
S 16/ Started button pressed
I 17/ I.C.O to "OPEN" (Back to closed if engine fails to start up)

[underlined] AFTER STARTING [/underlined]:-
1/ "Ground to Flight" to “flight”
2/ Booster coil “OFF”
3/ Check engine temp. and pressures
4/ Test operation of flaps and bomb doors.
5/ Check vacuum change over cock.
6/ Carry out running up checks

[underlined] BEFORE TAXYING [/underlined]:-
1/ D.R. compass to "ON" then to "SETTING"
2/ U/C lights change over switch, check it.
3/ Mixer box to intercom. position.
4/ Brake pressure 150 lb[symbol] min.
5/ Bomb doors closed
6/ Oxygen and intercom, check with rest of crew.
7/ Altimeter set to allow no lag.

[page break]

8/ TR1196 Ground check.
9/ Magneto switchs locked up.
10/ Auto controls main switch "OFF"
11/ Navigation lights as required.

[underlined] DRILL OF VITAL ACTION [/underlined]:-
1/ Auto Controls clutch "IN"
2/ Auto Controls clutch "OUT" (M.C.C)
3/ Air intake "COLD"
4/ Friction nut tight
5/ Flaps 15° - 25°
6/ Fuel No. 2 tanks with No. 1 + 2 booster pumps "ON" Master Cock "ON"
7/ Supercharger to "M" Gear
8/ Trimmers set by pilot.
9/ Radiator flaps outboard "OPEN" Inboard "AUTO"
10/ Boost cut lever as required.
11/ Pitot head switch "ON"
12/ Pneumatic pressure 150 lbs[symbol]" min.
13/ Prop. Max R.P.M.

[underlined] IMMEDIATELY [sic] BEFORE “TAKE OFF” [/underlined]:-
1/ Final check on eng temp’s & pressures.
2/ All unnecessary lights "OFF"
3/ Directional Gyro set to "ZERO" and uncaged
4/ Engines cleared

[page break]

[underlined] PYROTECHICS [sic] [/underlined]:-
Verey Pistol:- 1 1/2" DIA
[underlined] Stowage [/underlined] – on top of front spar near hydraulic reservoir
[underlined] Firing Piont [sic] [/underlined] in the roof immediately above stowage. This pistol may be loaded without removing from the firing point by W/O.

[underlined] Signal Cartridges [/underlined]:-
Types in use:-
[underlined] SINGLE STAR [/underlined] - one colour
[diagram] Colours used – Red (7 secs) Green (7 secs)
Ruby (8 secs) Yellow (8 secs).
[underlined] Note [/underlined] – as red is used for distress its rim is milled to enable it to be identified easily.
[diagram] [underlined] TWO STAR [/underlined] – Changing colour.
Combinations – Yellow to Green (5 & 4 secs)
White to Green (3 and 8 secs)
[underlined] DOUBLE STAR [/underlined] – Combinations
Green – Green
Green – Red
Red – Red
Red – Yellow
Yellow – Yellow
Green – Yellow

[underlined] ILLUMINATING CARTRIDGES [/underlined]:-
Used as a reconnaisance [sic] flare – 10 sec
Note:- Must not be used below 2,500 ft

[underlind] BROWN & WHITE SMOKE PUFFS [/underlined]:- Marked by [indecipherable word] symbols. Used by meteorological people to ascertain speed and direction of the wind

[underlined] DESTRUCTION INCENDIARY [/underlined]:- 1 1/4 lbs
Minimum of 2 carried opposite navigators table
[underlined] Inst. [/underlined] Remove tape and safety cover and strike cap.

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[two diagrams and chart]

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[underlined] FIRST AID OUTFIT [/underlined]:- 3 per A/C by Enterance [sic] & Exit door.
1/ Ampoules of iodine, 30 minims in each.
2/ Ampoules of morphia [sic] (syringe in tin box with labels). Remove hood, press stylet (wire in needle) down until it punctures top of capsule. Remove stylet. Hold syringe needle upwards and press capsule until a bead of morphia [sic] appears at top of needle. Then pinch up skin of arm or leg and insert needle beneath skin obliquely and empty contents by squeezing capsule
3/ Anti burn in 4oz tube.
4/ Triangle bandages.
5/ Dressings (Shell)
6/ Adhesive plaster – 1" in tin.
7/ Scissors – stretcher bearer.
8/ St Johns tourniquet

[page break]

Vol. II Pt. II Issued by A.M. to a Command to modify and re-issue it as Maintainance [sic] Schedule Issue II, it is divided into two sections:- 1/ Between flight and daily inspections 2/ Minor and major inspections

[underlined] Section I [/underlined] is issued in sub-sections to cover allied trades
A – Airframes
B – Engines
C – Instruments
D – Electrical
E – Wireless
F – Armourment [sic]
Listed on this sub-section is a between flt. and daily inspection.

A [underlined] between flight inspection [/underlined] is an examination of A/C refueling etc. after flight within the daily inspection period of 24 hrs, no record is kept of this inspection.
A [underlined] Daily inspection [/underlined] is carried out ever [sic] 24 hrs, even if the plane does not fly. For ease and avoidance of mistakes the inspectional items in the A/C are devided [sic] into groups U/C – Undercarraige [sic]
C/O – Cockpit
F/U – Fuselage
T/A – Tail Assy.
P/L – Main planes
G/E – General

On the completion of D.I. it is signed for in the F700 or if away from base in F.700A.

When the responcability [sic] of the D.I. is the F/E's he will complete the inspection on Airframes, instr, engines, elec,

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[underlined] INDENTIFICATION [sic] OF PIPE LINES [/underlined]


[page break]

Main wheel tyres = 43 lbs[symbol]"
Tail wheel tyres = 54 lbs[symbol]" or 60 lbs for later A/C.
Oleos - fully extended = 995 lbs[symbol]"
Oleo - Tail = 650-700 lbs[symbol]"
Emergency air U/C & B/D = 1200 lbs[symbol]"
Nitrogen = 1800 lbs[symbol]" + or - 200.
Hydraulic Acc. (black oil) = 220 lbs[symbol]"
Oxygen = 1800 lbs[symbol]"
Pneumatic Pressure Max = 300 lbs[symbol]"
Pneumatic Pressure Min = 150 lbs[symbol]"

[underlined] Boost Regulator - Faults. [/underlined]
High Boost – 1/ Damaged aneroid casing or dome nut leaking
2/ Failed aneroid
3/ Piston valve stuck down or relay piston forward

Low Boost – 1/ Piston valve stuck in UP position or relay piston to rear
2/ Linkwork to aneroid arm broken
3/ Line to boost gauge leaking
4/ Boost guage [sic] leaking

Fluctuating Boost – 1/ Sluggish piston valve or relay piston
2/ Slack control rods
3/ Oil in differential thick

[page break]



[underlined] Servo Piston [/underlined] – [underlined] 2 Small holes [/underlined] to prevent surging of piston when the valve returns to nuetral [sic].
[underlined] Spring [/underlined] behind piston to prevent the butterfly movement from moving piston at normal cruising

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2850 + 9. [underlined] MAX. CLIMB [/underlined]


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[underlined] Rated Boost [/underlined]:-
Highest boost engine may be fun for considerable time

[underlined] Rated Altitude [/underlined]:-
Highest altitude that rated boost can be maintained with International R.P.M.

[underlined] International R.P.M. [/underlined]
Highest RPM engine is designed - to run for considerable period of time.

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(a) PORT OUTER (b) Port inner (c) STBD. INNER (d) STBD. OUTER
(a) A.C. Generator "GEE" (b) D.C. Generator (Main Elec. Services) (c) DITTO. Pt. (d) A.C. Generator "H2S"
(b) HYDRAULIC PUMP (General Services) (c) DITTO PT.
(b) "PESCO" Pump (Panel) (c) DITTO P.T. (Bomb/s)
(b) R.A.E. Compressive (Auto-Controls "Ginger") (c) HEYWOOD Compressive (Pneumatic System)
(a) (Rear Turret) (b) HYDRAULIC PUMP (Mid Under Turret) (c) (Front Turret) (d) Mid Upper Turret)
(b) NOTE – Change over Cock for "Pesco" pump.

[underlined] MERLIN'S XX 22, 28 & 38 ENGINE LIMITATIONS
(a) MAX-TAKE OFF – (Boost cut out [underlined] NOT [/underlined] pulled) Throttle lever through gate (b) M (c) 3000 (d) + 14 MERLIN XX + 12
(a) MAX CLIMB – ([underlined] ONE HOUR LIMIT [/underlined]) (b) M&S (c) 2850 (d) + 9 (e) 125 (f) 90
(a) ECON CLIMB – ([underlined] CONTINUOUS [/underlined]) (b) M&S (c) 2650 (d) +4 (e) 105 (f) 90
(a) COMBAT CONDITIONS – ([underlined] 5 MIN LIMIT [/underlined]) (b) M & S (c) 3000 (d) +14 (e) 135 (f) 105
(a) (Cut out pulled) (b) M&S (c) 3000 (d) +16 (e) 135 (f) 105
(a) MAX. CONTINUOUS (No time limit). (b) M&S (c) 2650 (d) +7 (e) 105 (f) 90.

[underlined] MERLIN 24 [/underlined]
(a) MAX. TAKE OFF. (Boost cut out NOT pulled (b) M (c) 3000 (d) +14
(a) MAX TAKE OFF (Boost cut out PULLED (b) M (c) 3000 (d) +18
(a) MAX CLIMB (1 HOUR LIMIT) (b) M&S (c) 2850 (d) +9 (e) 125 (f) 90.
(a) ECON. CLIMB (NO LIMIT) (b) M&S (c) 2650 (d) +4 (e) 105 (f) 90.
(a) MAX. CONTINUOUS (No time limit) (b) M&S (c) 2650 (d) +7 (e) 105 (f) 90
(a) COMBAT (5 MIN. LIMIT) (b) M (c) 3000 (d) +18 (e) 135 (f) 105
(b) S (c) 3000

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[underlined] GROUND RUNNING AT DISPERSAL [/underlined]:-
It is assumed that the routine checks have been carried out, and engines are ready to be started.

Assatain [sic] from the ground crew if they are ready. When they are ready, turn on booster pumps for tanks selected (should be No 2.) and main mag switchs on, and booster coil on. Give signal to ground crew who will shout "Contact" F/E repeats "Contact" [inserted] puts on master full cock [/inserted] and presses starter button (As engine is turning ground crew will be priming – engine runs on priming only untill [sic] I.C.O is put to "Engine On" position) The F./E. will switch I.C.O to "Engine On" position after engine has fired on priming system, (Ground crew will keep priming untill engine runs evenly.) When all four engines are started switch "OFF" booster coil and Ground to Flight switch to "Flight"

1/ Check all oil pressures again
also functinal [sic] mag. check. change to No. 1 and switch off pump
2/ Let engines warm up (R.P.M. 1000 – 1200) until the min. temp have been reached (i.e. that is oil 15°C coolant 60°C, change back to No. 2.
3/ After min. temps have been reached, switch on "Over ride" for radiator flaps
4/ Open up throttle to "0" boost, and exercise the prop. by moving R.P.M. lever steadily down to minimum and up to max. Before moving lever from fully min allow R.P.M. lever to settle, same applies when moving from F.Max. down to min on second exercises. Repeat exercise until satisfaction is received from C.S.U.
[deleted] 5/ Leave R.P.M. lever at fully max. [/deleted]
5/ Select 2000 R.P.M. with R.P.M. lever. This is to ensure C.S.U.s constant speeding.
6/Move throttle lever from Zero up to +4 boost

[page break]

and check that R.P.M. remains at 2000. This checks the C.S.U.
7/ With throttle lever selecting +4 proceed to move R.P.M. lever steadily down to fully min. and then up to fully max, and check boost remains at +4 this checks boost regulator
8/ Leaving R.P.M. lever at fully max. (It remains at fully max for remainder of test.)
Move throttle lever up to the gate and note if static R.P.M. of 2850, and rated boost +9, is obtained
9/ Move throttle lever through gate and check for 3000 R.P.M. boost +14, DO NOT STAY AT THIS POSITION LONGER THAN IS NECESSERY [sic] TO GLANCE[?] AT INSTRUMENTS.
10/ Pull throttle lever back to gate (2850 +9) and check mags. Max. permissable drop on either mag. 100 R.P.M.
11/ Pull throttle back untill ZERO boost and change from"M" to "S" check that R.P.M. drops a little and boost rises a little. Change back to "M".
12/ Pull throttle lever back untill R.P.M. is approx. 1000 – 1200 and check temps. If excesive [sic] allow engine to cool "off". When temps O.K. switch "OFF" overide
13/ Pull throttle smartly back to slow running 450-600
14/ Switching "off" – I.C.O. to I.C.O. position (Switch down) [deleted] and when engine [/deleted] Master fuel cock "off"
Mags "off"

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[charts and diagrams]

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Recommended air speeds for LEVEL CRUISING for MAX. RANGE:-


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[underlined] Rules for a descent [/underlined] (flying for Max. Range) [inserted] 4 or 3 [/inserted]
(Say) from level cruising at 27,000 ft we descend to Sea Level.

Leave throttle lever at Gate, and decrease R.P.M. until I.A.S 160 (recommended) is obtained, As height is lost, so boost will rise – consequently R.P.M. can be further decreased, IA,S. still being maintained. As we descend further, R.P.M will gradually be decreased When R.P.M reaches just below 2300, increase same up to 2500 and change down to "M" Gear. Again on further descent R.P.M continues to be lowered. When RPM reaches minimum (1800) IAS can be accepted above recommended figure 160 until the boost rises above +4 (this will most probably be noticed at 3000 ft approx.) When the boost does rise above +4 it becomes necessary to throttle back to +4 I.A.S. thus obtained with 1800 +4 is still accepted even though it be above the recommended figure of 160.


[underlined] Low Level Cruising for Max. Range. [/underlined] (approx 3000 ft and below)
1/ R.P.M to 1800 [inserted] (min) [/inserted]
2/ Throttle to +4 [inserted] (Gate) [/inserted]
3/ Accept I.A.S. thus obtained with 1800 +4 (In other words, ignore I.A.S.)

[underlined] Endurance Flying [/underlined]:- [inserted] LOW & SLOW [/inserted]
In this case we desire to stay in the air the longest possible period of time, on a certain quantity of fuel. We are not concerned with "miles per gal" but rather with "hours in the air per gal."

Conditions:- 1/ R.P.M. 1800
2/ Flaps somewhere between 15° – 20°
3/ Throttle back until a I.A.S of approx 130 obtained.
[underlined] DO NOT CONCERN YOURSELF WITH BOOST [/underlined] (will be below +4
4/ Fly as Low as is possible with safety [symbol] This should in any case be below [underlined] 3000 [/underlined]

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Note: With Endurance conditions although "hours in the air per gal" is good. "A.M.P.G" is adversily [sic] affected.

Therefore if a long distance remains to be travelled and petrol is low, END, CONDITIONS SHOULD NOT BE USED. The correct condition to use would be those for "Max Range"

[underlined] 2 ENGINE DESCENT [/underlined]


Typical example of Operational Climb:-
A.U.W. 65,000 lbs. climb 2650 +4 I.A.S. (157) to full Throttle Hieght [sic] (14000). Change to "S" Gear, and increase power to Max. Climb 2850 +9, IAS (153). Climb 20,000 ft. At 20000 ft leval [sic] out I.A.S. (160) Use 1000 lbs (150 gals fuel) before climbing any further, after this fuel is used continue to climb in max. power 2850 +9 IAS. 153

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Calculation of fuel required:-
The absolute range of a Lancaster is 1.25 A.M.P.G. but it is assumed that the A/C can only travel 75% of this figure as [underlined] track [/underlined] miles per gall. (i.e. Lanc. A/C will travel .94 track p. gall).

We have to allow 200 gallon running up, take off, etc. [symbol] Fuel required = 200 + (Estimated track miles)/.94
e.g. for trip of 1000 track miles = 200 + 1000/.94 gallons
= 200 + 1064 = 1264

[deleted] [underlined] Practice Feathering [/underlined]:-
1/ Booster pump "on"
2/ R.P.M. "Min"
3/ Throttle lever to give moderate cruising boost ([indecipherable word])
4/ Press feathering button (will spring out when prop fully feathered)
5/ I.C.O. to I.C.O. position
6/ Switch "off" mags. after engine has stopped [/deleted]
[inserted] “DUFF GEN” [/inserted]

Feathering:- [inserted] R.P.M = 1800 [/inserted]
1/ I.C.I. & Master fuel cock turned "OFF" before feathering
2/ Press feathering button and hold just long enough to ensure it stays in
3/ Throttle back and when engine stops, switch mag "OFF"
4/ Throttle lever can be put back out of way (If this was not done on inboard engines U/C horn would blow)

Unfeathering:- 1/ A/C flying at normal cruising speed 160 IAS to avoid any risk of over speeding.
2/ R.P.M. min., Throttle lever slightly open, Mags "ON"
3/ Fuel booster pumps "ON"
4/Master fuel cock "ON" just before pressing button.
5/ As engine starts turning I.C.O. to "ENGINE ON"
6/ Keep button pressed in until R.P.M. reachs [sic] 1500 & not more 1800
7/ Then pull button "OUT". Prop should now return to C.S. operat[missing letters]
8. If engine is cold, allow to warm up.

[page break]

1/ Prepare to land
2/ Flaps 20°
3/ U/C Down
4/ 2650 +1
5/ Flaps 30°
6/ I.A.S. called by Navigator
7/ "Flap – Revs" (Flaps fully down - 2850)
8/ After touching down F/E checks throttles fully back.

[page break]


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1/ Explain basic principles of the operation of the 2 speed supercharger
2/ Why is "S" Gear not used at low altitudes
3/ Explain why at T.O. boost of +14 (throttle through gate cut out [underlined] not [/underlined] pulled) drops off as soon as altitude is ganed [sic], whereas +14 boost which is obtained by pulling the cut out can be maintained at any altitude up to approx. 6000 ft.
4/ Explain why mixture strength would tend to become rich if no altitude Mixture Control was fitted to a carb.
5/ What indication would you expect to find if coolant system had an internal leak.
6/ What could be wrong if the coolant boiled
7/ Between what boost is the A.B.C. able to regulate – explain
8/ C.S.U oil is not able to feather airscrew – why?
9/ Why is a higher pressure of oil required for unfeathering process against that required for feathering.
10/ Describe the operations you would expect to make if you were briefed to fly to 14,000 ft at [underlined] Eccon climb [/underlined] condition and then continue on to 20,000 ft at [underlined] Max climb [/underlined] at 20,000 you leval [sic] out and cruise

[page break]

[underlined] Boost Reg [/underlined]
1/ What happens if at 16000 ft approx. "S" gear is engaged at Econ climb condition. What has to be done to remain at Econ climb conditions (Boost rises, throttle back)
2/ Why is the Atmos. cock fitted
3/ Why is spring fitted behind piston.
4/ Why are bleed holes fitted in piston
5/ If at sea leval throttle was moved from S.R. position (with R.P.M. lever at max) up to (say) +4 boost R.P.M. would be approx 2550 (fully fine prop)
Question – If boost cut out was now pulled would boost increase to +9

[underlined] Coolant [/underlined]
1/ If at 15000 ft temp guage in cockpit reads 112°c and a bullet pierces top of header tank, what would happen 1/ To gauge reading temp (Drop to approx 87°c)
2/ To gauge reading oil (Go up)
3/ To engine (Temp rise)
4/ To coolant (Coolant Evaporate)

2/ Cruising along at say 14000 coolant temp was noticed to rise without any apparent reason and at same time oil pressure started to fluctuate. What could be the trouble (Coolant leak into sump oil)

3/ Why is coolant pump fitted

Boost Reg.
1/ Describe operation of B. Reg. during Econ Climb
2/ Describe operation of B. Reg during Max Climb
3/ How is butterfly controled [sic] at Boosts below + 2
4/ What would happen if aneroid was punctured.

[underlined] General [/underlined]
1/ Describe lubrication system
2/ Why is a fuel valve fitted on Strom. Carb.

[page break]

3/ What operates boost enrich valve.
4/ When does boost enrich valve open (2650 +7)
5/ What is the idle needle – why is it fitted – when does it operate (1700 RPM + below – S.R. – meters fuel)

1/ How would you know if the thermostat was U/S
2/ Would you get any increase in Boost if the cut out was pulled at +2 at S.L.
3/ What happens to jet size on A. Mix low on S.U. as height is gained.
4/ At which height is carb. supplying most fuel,
a) 2650 +7 at sea level
b) 2650 + 7 at 16,000 ft.
5/ Climbing at (say) 2650 on a Boost is +2 (approx 16,000 ft "M" Gear. What indication would you have in cockpit if somebody changed to "HOT AIR"
6/ When is Poppet valve in Stromberg fully closed.
7/ Would chamber "C" be primed with I.C.O. in I.C.O position.
8/ When are Rad flaps 1/2 open
9/ What is the speed of magneto distributor – 1/4, 1/2, 3/4, 1 1/6
10/ Engine is running at 2200 +4 (Merlin 22) and boost enrichment aneroid chamber developes a leak – does mixture become a) Weak
b) rich
c) Remain unchanged.

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(a) 50 Ammeters (b) 40 Voltmeter (c) Procedure.

(a) Balanced (b)29 (c) Nil.
(a) unbalanced (b) 29 or less (c) Nil.
(a) One discharge + other charge (b) 29 or less (c) Switch off generator showing a discharge.
[deleted] 129 [/deleted]
(a) Unbalanced (b) +29 (c) Switch off generator showing a [deleted word] charge greater than other
(a) One discharge + one charge (b) +29 (c) Switch off gen. showing charge.
[symbol] (a) Balanced (b) +29 (c) Switch [underlined] both [/underlined] off.. be eccon.

[diagram] How would you morse on head light

To morse head light – Headlight switch on - MEP to signal. Down ident. switch to morse & tap key

[page break]

[underlined] FACTS [/underlined]:-
1/ RANGE FLYING – fly against min drag
– fly at I.A.S. for min drag.
(Recommended operating speed – max. range – weak mixture.)

2/ CRUISING – fully loaded out.
Up to 15000 ft – 170 (165 M.P.H. I.A.S)
At 20,000 in "S" – 160 (155 M.P.H. I.A.S.)
Lightly loaded home – home – 160 (155 M.P.H. I.A.S.)

3/ RANGE FLYING - IAS heavy is greater than I.A.S. light
With fixed wt. and fixed I.A.S. move T.H.P./B.H.P./GPH. are required as height increases.

T.H.P./B.H.P./G.P.H. are least. 1/ Fly [underlined] LOW [/underlined] 2/ Fly [underlined] SLOW [/underlined] The best fuel econ. (that is i.e. best A.M.P.G) is got by working the rule "HIGH BOOST & LOW REVS."
A throttled engine is not econ. Other things being equal the best A.M.P.G. is got at Full Throttle position

It is recommended to fly at or near the full throttle position, working high boost, low reves [sic], and accept whatever I.A.S. is obtained even though this is not the econ. I.A.S.

6/ RANGE FLYING – flying too [underlined] fast [/underlined] or too [underlined] slow [/underlined] will reduce A.M.P.G. and range.

7/ HOT AIR will materially reduce A.M.P.G.

145 (140) M.P.H. IAS to 20000 ft
140 (135) M.P.H. IAS from 20,000 to 25,000
135 (130) M.P.H. IAS above 25,000

9/ CLIMB – MAX. RANGE – Weak Mixture
155 (150) M.P.H. IAS 2650 + 4

[page break]

A Dent came in on 12-7-55 due out on 20-7-55 G Dent the same for tocells.

[indecipherable words]

[page break]


DRAG:- 1/ Constructional or form drag.
2/ Skin Friction (Rivets, paint, dope etc.)
3/ Wing tip vortices (Induced drag) High speeds, but at low speed mostly Lanc:- 4000-5000 ft lbs drag.
4/ Compressiblity [sic] (Air Compression) Greatest at high speeds.

[symbols] [deleted] chese [/deleted] chak
brave [symbol] flame [symbol] grave [symbol] shave [symbol] stone [symbol] strong [symbol] shame [symbol] blame [symbol] [two deleted words] joke [symbol] [deleted words] gase [symbol] blasé [symbol] planes [symbol] [deleted word] gate [symbol] ate [symbol] mate [symbol] cake [symbol] [two deleted words] cave [symbol] [deleted word] bare [symbol] pale [symbol] [deleted] der [/deleted] dare [symbol] [deleted word] hear [symbol] more [symbol] hate [symbol] [deleted word] home [symbol] hope [symbol] lame [symbol] same [symbol] game [symbol] made moste [symbol] note [symbol] late [symbol] safe [symbol] make [symbol] talk [symbol]

[underlined] Centre of Pressure. [/underlined] That point where the TOTAL AIR FORCE acts.

[underlined] Lift: [/underlined] (lbs) – that part of T.A.F. which is at right angles to the wind line or of direction of motion.
Drag (lbs) – that part of T.A.F. which is in LINE with the wind line at direction of motion.

rose [symbol] rat [symbol] rope [symbol] [deleted word] gave [symbol] task [symbol] [deleted word] sake [symbol] name [symbol] tame [symbol] lake [symbol] lame [symbol] date [symbol] rage [symbol] done [symbol] woke [symbol] [deleted lack [/deleted] lace [symbol] shape [symbol] drove [symbol] slope [symbol] face [symbol] place [symbol] grace [symbol] trase [symbol] snore [symbol] [deleted word] smoke [symbol] spoke [symbol] plat [symbol] [deleted word broke [symbol] whale [symbol] stile [symbol] shake [symbol]

[underlined] OPTIMUM ANGLE [/underlined] – is the angle of attack where L/D ratio is a maximum (4° aerofoil 9° Lanc A/C)

[underlined] LIFT [/underlined] – Depends on: - also Drag
1/ Slope and angle of attack
2/ Density of air
3/ Plan area of lifting surface
4/ (Speed)2


[page break]

[underlined] AIRSPEEDS. [/underlined]
I.A.S. = m.p.h. on A.S.I
R.A.S. = I.A.S. - Position error.
T.A.S. = R.A.S. x altitude correction factor
Track speed = T.A.S. +/- Wind m.p.h.

[underlined] POSITION ERROR CORRECTION – LANC I [/underlined]

CHANGES OF WT & SPEED – Econ. Cruising speed will be [underlined] reduced [/underlined] when wt. is less

[underlined] ELECTRICS [/underlined]:-
Use of Relays.
1/ Elimination of heavy cables to control
2/ Suppression of sparks under heavy loads
3/ Elimination of "voltage drop"
4/ Remote Control.

[underlined] CARBURATION [/underlined]:-
Detonation:- too rapid burning
Effects – 1/ Excessive temp.
2/ Excessive pressure
3/ Loss of Power.
4/ Softening, warping, cracking up of cyl. & piston

[page break]

[underlined] Causes of Detonation [/underlined]:-
1/ Boost too high *
2/ Compression too high
3/ Moderate boost, mixture too weak
4/ R.P.M. too low.
5/ Spark too far advanced
6/ Hot spot (eg. carbon use of hot air)
7/ Octane number too low.


[underlined] DRAG & I.A.S. [/underlined] If the Wt and IAS remain the same then the drag is the same at all hieghts [sic]. The reduction in drag due to the increase in air density is off set by the increase in drag due to the increase in T.A.S.

[underlined] HIGH BOOST & LOW REVS:- [/underlined]
1/ Mixture must be weak. That is keep the boost down to +4 (+7).
2/ Boost and revs must be worked so that over heating does [underlined] not [/underlined] occour [sic].
3/ Revs must [underlined] not [/underlined] be dropped too low – roughrunning generator cuts out

[page break]

[underlined] ADVANTAGES of HIGH BOOST & LOW REVS [/underlined]:-
1/ Fuel compsumption [sic] reduced (A.M.P.G. increased)
2/ Less power wasted by supercharger, mags, etc.
3/ Throttle butterflies set wider giving a higher thermal efficiency
4/ Charge runs cooler giving higher volumetric eff.
5/ Friction losses reduced – engine has easier time
6/ Oil consumption reduced.

[underlined] EFFECT OF WINDS [/underlined]:- not fully known.
Rough rule – Increase I.A.S. by 5 M.P.H. for every 50 M.P.H. head wind.
I.A.S. reading is not effected by head wind
A.M.P.G. is not effected by head wind.
Track miles per gallon is effected by head wind.
Track speed equals T.A.S. – Head wind M.P.H.

Absolute range equals range in still air
Practical range equals 75% of absolute

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Engine log:- (Full tanks)
1/ Run off 40 galls. (No. 2) for taxi, warm up T.O.
2/ Make an entry at most every 20 min
3/ Make an entry every time engine conditions or altitude of A/C are changed
4/ Make an entry every 1 hour from end of T.O.
5/ Make an entry every 1 hr 20 mim [sic] end of T.O.
6/ You can run 5 min over time (2 to 5)


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[underlined] Facts [/underlined]

Use of hot air will materially reduce A.M.P.G.

Climbing Max. Rate:-
145(140) MPH, IAS, to 20,000 ft
140(135) MPH from 20,000 to 25,000 [sketch]
135(130) MPH above 25,000 ft
Climb Max. Range - Weak Mixture
155(150) M.P.H., IAS, at +4/2650


Facts – Climb with constant throttle & Rev setting. Rate of Climb will increase if I.AS. is reduced

For constant throttle & rev settings the rate of climb will decrease if I.A.S. is kept fixed.


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[back cover]



J Dent, “John Dent engineer course notebook,” IBCC Digital Archive, accessed March 26, 2023,

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