Engineering exam questions

MTwellsE171780-151026-15.pdf

Title

Engineering exam questions

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A folder containing a paper entitled 'No.23 Course First Three Weeks Engineering Examination', a second paper entitled 'No. 36 Course Pilots Intermediate Exam "Y" Squad" Engineering', a third paper 'School of Flight Efficiency Final Paper, Part II', handwritten notes, a fourth paper 'School of Flight Efficiency Final Paper, Part I', a fifth paper 'No 1 Flight Efficiency Course, Aerodynamic Examination', a sixth 'No 1 Flight Efficiency Course, Engine Examination', a handwritten note of F/O Humphries address, Effect of Range with Head Wind and Anti-icer System.

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A notebook with six typewritten and six handwritten sheets

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IBCC Digital Archive

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This content is available under a CC BY-NC 4.0 International license (Creative Commons Attribution-NonCommercial 4.0). It has been published ‘as is’ and may contain inaccuracies or culturally inappropriate references that do not necessarily reflect the official policy or position of the University of Lincoln or the International Bomber Command Centre. For more information, visit https://creativecommons.org/licenses/by-nc/4.0/ and https://ibccdigitalarchive.lincoln.ac.uk/omeka/legal.

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Identifier

MTwellsE171780-151026-15

Transcription

Form 2007

[Underlined] ROYAL AIR FORCE [/underlined]

F/O TWELLS

ENG QUESTIONS

F/O TWELLS

[Underlined] NO. 23 COURSE FIRST THREE WEEKS ENGINEERING EXAMINATION. [/underlined]

[Underlined] ENGINE [/underlined]

(a) What symptoms would lead you to expect that an engine was detonating during flight.
(b) How would you verify this?
(c) What subsequent action would you take?

[Underlined] CARBURETTOR [/underlined]

(a) Why are you instructed, when handling the Claudel Hobson carburettor, never to use a throttle lever position midway between E.C.B. and R.B. (Exception – Halifax 3).
(b) If the power valve on a Claudel Hobson carburettor had jammed open, what probable effect would result when cruising at a very low attitude (throttle engine).

[Underlined] PROPELLOR [/underlined]

A fixed pitch propeller, when fitted to a normally aspirated engine, operates with reasonable efficiency.
In view of this fact, why is flying in fixed pitch with the electrical propeller not advocated when fitted to a [underlined] supercharged [/underlined] engine.

[Underlined] LUBRICATION [/underlined]

What symptoms experienced during flight, would lead you to diagnose a choked scavenge filter in the engine. What action would you take?

[Underlined] HANDLING [/underlined]

How would the following influence your choice of height and/or airspeed giving reasons for your decision.

(a) Airframe icing
(b) High temp. and unstable air
(c) Weight reduction due to parachute load.

[Page Break]

F/O TWELLS

[Underlined] NO. 36 Course [/underlined]

[Underlined] Pilots Intermediate Exam [/underlined]

[Underlined] “Y” Squad [/underlined]

[Underlined] Engineering [/underlined]

[Underlined] SPERRY [/underlined]

1. (a) What are the follow [sic] upcables and why are they fitted? [diagrams inserted]
(b) Tabulate procedure for engaging Sperry in Flight

Marks 20

[Underlined] SERVICING [/underlined]

2. (a) Where would you find information that would tell you when the next Minor inspection is due for your aircraft?
(b) Wh at [sic] advantages [sic] has progressive servicing over the old method of servicing?

Marks 20

[Underlined] ELECTRICS [/underlined]

3. (a) If two accs. Are connected in parallel each of 12v 88 AMP/HR what would be the capacity?
(b) Show how these acc. are connected in parallel?

[Underlined] RANGE FLYING [/underlined]

4. (a) What is the specific fuel consumption?
(b) What are the rules for keeping the SFC to a minimum?
(c) If an engine is developing 800 BHP and is doing so using 50 GPH what is the S.F.C. ?

5. If the weight of an A/C is decreased, what happens to?
(i) Induced drag
(ii) Parasite drag
(iii) Totaldrag [sic]
(vi) Recommended speed

Marks 40

[Page break]

F/O TWELLS

[Underlined] School of Flight Efficiency. [/underlined]

[Underlined] Final Paper, Part II [/underlined]

[Underlined] Question 1 [/underlined] (30 Marks)

Show how specific air range varies with an increase of parasite drag, assuming constant S.F.C. and propeller efficiency.

[Underlined] Question 2 [/underlined] (40 Marks)

Why is performance at full throttle best:-
(a) for range.
(b) for speed?

[Underlined] Question 3 [/underlined] (30 Marks)

Why is performance at sea level best for endurance?

Under what circumstances would a height above 1,000 feet be used?

[Underlined] Question 4 [/underlined] (30 Marks)

Write brief notes on:-

(a) Vertical Climb
(b) Range Descent.
(c) Delayed Climb.

Answer Question 2 and two others. Wherever possible illustrate your answer with a diagram or graph which should be large and clear.

[Page break]

[Calculations]

[Page break]

F/O TWELLS

[Underlined] School of Flight Efficiency [/underlined]

[Underlined] Final Paper, Part I [/underlined]

[Underlined] Question 1 [/underlined] (70 Marks)

Two aircraft of the same type and weight are flying at the same T.A.S. (repeat T.A.S.) which in each case gives an I.A.S. above that for minimum drag. Propeller efficiency and S.F.C. are the same in each case, but one is at sea level and the other at 5,000 ft. Which will have the greater:-

(a) I.A.S.
(b) Angle of Attack.
(c) Total Drag. [inserted] LES [/inserted]
(d) Induced Drag. [inserted] MORE [/inserted]
(e) Parasite drag. [inserted] LESs [/inserted]
(f) Power Required.
(g) Rate of Fuel Consumption.
(h) Specific Air Range.

[Underlined] Explain each answer briefly. [/underlined]

[Underlined] Question 2 [/underlined] (15 Marks)

An aircraft operates at constant R.P.M. i.e. decreasing S.F.C. with increased power. Explain why the best speed for range is above the speed for minimum drag.

[Underlined] Question 3 [/underlined] (15 Marks)

Explain how the best speed for range varies with an increase in weight, assuming constant S.F.C. and propeller efficiency.

[Page break]

F/O TWELLS

No. 1 FLIGHT EFFICIENCY COURSE, AERODYNAMIC EXAMINATION.

Ques. (1) Forty Marks.

(a) Why is the ICAN Standard Atmosphere necessary for aviation?
(b) An aircraft is flying at 1200ft. [inserted] 12,000 [/inserted] in standard atmospheric conditions. What is the pressure in MBs? What is the % density? What is the temperature in [deleted] o [/deleted] [inserted] ° [/inserted] C and “ [deleted] o [/deleted] [inserted] ° [/inserted] “ Absolute? For the same altimeter reading and temperatures [deleted] _ [/undeleted] [inserted] – [/inserted] 15 degs.what is the pressure in MBs? What is the percentage density?

Ques.2. 30 marks.

An aircraft weighing 22000lbs is flying at 6000ft., where the altitude factor is 1.4 at 180 knots I.A.S. with 1560 B.H.P. The propeller efficiency is 75% and the drag 2000lbs. Is the aircraft flying level, climbing, or descending and if so at what rate?

Ques. 3. 30 Marks

An aircraft with a constant speed propeller is flying at a given R.P.M. and Boost. If (a) boost is increased at constant R.P.M, (b) R.PM. [sic] is increased at constant boost, what happens to the pitch of the propeller and why? Explain briefly possible inefficiency at high boost and low R.P,M. at low speed.

[Page break]

No 1 FLIGHT EFFICIENCY COURSE. ENGINE EXAMINATION. F/O TWELLS

Ques. 1.With the aid of graphs explain,

(a) Why the Brake Thermal Efficiency is increased with increasing boost at constant R.PM. [sic]
(b) Why the B.TH.E. is decreased with increasing R.P.M. at constant boost? (c) What happens to S.F.C. in each case?

Ques. 2. If at 7000ft. atmospheric temperature were -10degs. C would the mixture strength be [inserted]/[/inserted] richer, weaker or unchanged compared to that for which the Carb. was designed, in the case of.,
(1) Pegasus(Claudel Hobson), (2) Twin Wasp, (Stromberg) (3) Rolls Merlin, (S.U.)

Give brief reasons for your answers.

Ques.3. At 7000ft, the engine settings required for 140 Knts [sic]. Are 2000 R.P.M. , zero boost,. What are the settings required for 2000ft?

(b) At 15000ft. settings required are2250 [sic] R.P.M.-3 lbs boost, what are the settings at sea level?

Ques. 4. What is S.F.C?
At Sea level an engine developes [sic] 1350 B.H.P. and consumes 78 G.P.H. At 3000ft. with same R.P.M. and boost develops 1400B.H.P. and consumes 81 G.P.H. What is the S.F.C. in Pints/B.H.P.hr. in each case? Account briefly for any difference. (Constant air/fuel ratio).

Ques. 5. Draw the Power / Altitude curve for a N.A. eng. At full throttle, and for same engine fitted with a [inserted] n [/inserted] E.D. Super-charger, with zero boost, max. permiss., and also for the same enginefitted [sic] with a Turbo-supercharger, zero boost, max. permiss.

(a) Enumerate and explain the advantage of a Turbo-superchager [sic]

[Page break]

184727 F/o Humphries

R.A.F.Dunkeswell

Nr Honiton

Devon

I

[Page break]

[Underlined] EFFECT OF RANGE WITH HEAD WIND [/underlined]

[Calculations]

[Page break]

[Underlined]ANTI-ICER [sic] SYSTEM. [/UNDERLINED]

[Underlined] PROPS [/underlined] Alcohol. glycerin is used.

4 U.S galls in tank at the bulkhead behind. the [sic] pilots seat 12V electric motor unit gear [indecipherable word] pump controled [sic] by switch on elec panel above pilots windshield.

Amount used controlled [sic] by rheostat on bulkhead at back of pilots seat

Windshield. fluid used Alcohol. contained in a 5 GALLS tank in right baggage compartment

hand pump rear co-pilots seat

Deicing Equipment deicing shoes on leading edge of wings tail and vertical stabilizers

Inflated by exhaust from: vac pump one on each engine

air lines go to a distributor

The cycle is as follows

Centre cells on left [inserted] out board [/inserted] and right main plane

[Page break]

Upper and lower cells on right and left outboard outer wing shoes

Center cells on right and left inboard wing

Upper and lower cells on right and left inboard

Each cycle takes aprox [sic] 8 secs

Tail shoes.

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Great Britain. Royal Air Force, “Engineering exam questions,” IBCC Digital Archive, accessed August 15, 2022, https://ibccdigitalarchive.lincoln.ac.uk/omeka/collections/document/7813.

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