D R Theory Exercise Book
Title
D R Theory Exercise Book
Description
An exercise book kept by Ted Neale recording notes about navigation theory. Training notes covering Dead Reckoning calculations and corrections, and post flight procedures.
Creator
Publisher
IBCC Digital Archive
Date
1943
Contributor
Rights
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.
Format
One exercise book with handwritten notes
Language
Identifier
MNealeETH1395951-150731-030
Temporal Coverage
Transcription
S.A. AIR FORCE
S.A. LUGMAG
[underlined] D.R. [/underlined]
Theory
EXERCISE BOOK
OEFENBOEK
E. Neale.
FOR USE IN
VIR GEBRUIK BY
AIR FORCE TRAINING SCHOOLS
LUGMAGSKOLE
[page break]
[underlined] Analysis of Air Exercises. [/underlined]
1/.
To determine the standard of accuracy of air navigation to which it is possible to rely.
2/. To isolate those errors of which errors can be practically eliminated by training & practice.
To fly from one point to another the navigator makes various calculations from which the E.T.A at the terminal point, the difference between the position that he finishes up & his destination is the nett error of the flight (the final error.) It is necessary therefore for the purposed of analysis an accurate pinpoint is obtained at or near E.T.A.
There are several errors to be taken into consideration, the result of these may be cumulative or may partially or wholly cancel one another out. Thus the final error in
[page break]
itself may not provide a reliable guide as to the accuracy of navigation.
Analysis must be made to determine the several errors individually, the sum of these errors named the cumulative error shows the error that would have been obtained in the most unfortunate circumstances with the errors operating in the same direction & sense. Examination of the cumulative error provides an average figure which may be taken as a guife to the accuracy of any particular crew, when on recco it may be taken as an indication of the accuracy of the sighting report from that crew, or whilst on a bombing sortie the ability to find their way to the target area.
[page break]
[underlined] The errors are divided into the following groups. [/underlined]
1/. [underlined] Calculation error [/underlined] due to incorrect plotting, calculation of courses to steer, times to alter course & E.T.A’s etc.
2/. [underlined] Wind change error. [/underlined] caused by the wind velocity(s) used by the navigator not being the true wind velocity(s) affecting the A/C
3/. The other error
Composed of errors due to incorrect piloting, faulty instruments etc.
[diagram]
[page break]
[diagram]
From the geographical point of departure the actual courses steered are laid off for distance corresponding to the T.A.S & time on each course. The final air position is called A. From A lay in W/Velocities used by plotting directions for distances corresponding to the Wind speed & time that each W/V is used, this position is B. then calculation error is B – X. X being proposed terminal point of flight. From A lay in W/V as above, this point is called C. BC is then wind change error. Plot actual posn of A/C on E.T.A. (D) DC is then other error. DX is final error.
[underlined] points to be noted. [/underlined]
1/.
Air Speed used must be T.A.S. i.e. check comparison of I.A.S.
2/. Time must be accurately noted.
3/ Errors are determined by measurement of distances on the plot, these errors are then expressed as a percentage of the total air distance flown, in order to provide a standard to compare navigation.
[underlined] Results of Analysis. [/underlined]
1/. It provides a standard of accuracy that can be relied on by a particular crew, this being an average of the acumulation [sic] errors on a number of flights.
2/. It shows any particular error which it may
[page break]
be possible to eliminate by further practice on the part of navigator & pilot ie inability to calculate W/V’s or steer courses.
[underlined] Accepted Standard of accuracy for A/C of Reconnaisance [sic] Type (ie Anson). [/underlined]
[table]
[diagram]
[page break]
[underlined] RUNNING FIX. BY Co & A.S. [/underlined]
Bomber Command method.
The advantage of this method is that it can be used to give an accurate running fix when TRACK & G/S are either unknown or not known with sufficient accuracy to give a good fix. i.e. when flying over the sea & unable to check drift. Whilst flying in or above cloud, while flying on a dark night. On these occasions track & g/s would not be known accurately, but the CO & a/s would be known.
[underlined] NOTE. [/underlined]
THIS METHOD CAN ONLY BE USED IF THERE HAS BEEN NO ALTERATION OF COURSE OR T.A.S SINCE LAST FIX OR PIN POINT.
CONSTRUCTION (A)
From last FIX or P.P. draw on Co (T) & mark in Air Posns for times of Posn lines (bearings) (D&E). From (A) draw any line A-B
[page break]
to cut the first Posn line at [underlined] C. [/underlined] Join D-C, through E draw a parallel to D-C to cut A-B at F. then F is the point through which to transfer 1st Posn line. If 3 posn lines are used first transfer 1st Posn line to last & then second Posn line to last.
[underlined] NOTE. [/underlined]
The accuracy of this method depends to some extent on the angle between the course & the line [underlined] AB [/underlined] which should be in the nature of 10 - 15. The D.R. track may be used as line A – B if the D – R drift is sufficiently large ie angle between Co & AB large enough.
[page break]
[diagram]
Line of radius of action can be calculated from a formula, or by putting ground speed out against ground speed home on back of computor, then looking for two numbers opposite each other on outer & inner scale the sum of which equals the duration of the flight in minutes. Point to turn is found by measuring distance calculated from G/S out and time for radius of action.
[page break]
[underlined] Radius of Action to Second or Moving Base [/underlined]
[diagram]
[page break]
[page break]
[calculations]
[page break]
[calculations]
[page break]
[calculations]
[page break]
[calculations]
[page break]
6/. Go to crew room & check up on small notices published in your absence, particularly your next standby.
[underlined] Bombing Recco [/underlined]
1/. Exact location.
2/. Layout of TARGET.
3/. Vulnerability.
4/. Damage done in previous raid.
5/. Tactical information.
a/. The visibility of the TARGET from different angles of APPROACH.
B/. Landmarks as an aid to low level attacks.
c/. Landmarks as an aid to night attack
d/. Enemy defences, fighters & A-A
e/. Met Information
[page break]
[table]
[underlined] PROCEDURE AFTER FLIGHT. [/underlined]
1/.
Aircraft met by NCO photographer. Hand to him your camera magazine & note of no of exposures & light conditions over target.
2/. Report immediately to the Ops room taking with you Forms 401 & 441 your maps & all notes made in the air.
3/. You are interrogated by S.I.O. & may here discuss verbally any assumption
4/. Sign & hand in forms 401 & 441
5/. Complete & sign photographic report, bombing report (BA), combat report (PILOT)
S.A. LUGMAG
[underlined] D.R. [/underlined]
Theory
EXERCISE BOOK
OEFENBOEK
E. Neale.
FOR USE IN
VIR GEBRUIK BY
AIR FORCE TRAINING SCHOOLS
LUGMAGSKOLE
[page break]
[underlined] Analysis of Air Exercises. [/underlined]
1/.
To determine the standard of accuracy of air navigation to which it is possible to rely.
2/. To isolate those errors of which errors can be practically eliminated by training & practice.
To fly from one point to another the navigator makes various calculations from which the E.T.A at the terminal point, the difference between the position that he finishes up & his destination is the nett error of the flight (the final error.) It is necessary therefore for the purposed of analysis an accurate pinpoint is obtained at or near E.T.A.
There are several errors to be taken into consideration, the result of these may be cumulative or may partially or wholly cancel one another out. Thus the final error in
[page break]
itself may not provide a reliable guide as to the accuracy of navigation.
Analysis must be made to determine the several errors individually, the sum of these errors named the cumulative error shows the error that would have been obtained in the most unfortunate circumstances with the errors operating in the same direction & sense. Examination of the cumulative error provides an average figure which may be taken as a guife to the accuracy of any particular crew, when on recco it may be taken as an indication of the accuracy of the sighting report from that crew, or whilst on a bombing sortie the ability to find their way to the target area.
[page break]
[underlined] The errors are divided into the following groups. [/underlined]
1/. [underlined] Calculation error [/underlined] due to incorrect plotting, calculation of courses to steer, times to alter course & E.T.A’s etc.
2/. [underlined] Wind change error. [/underlined] caused by the wind velocity(s) used by the navigator not being the true wind velocity(s) affecting the A/C
3/. The other error
Composed of errors due to incorrect piloting, faulty instruments etc.
[diagram]
[page break]
[diagram]
From the geographical point of departure the actual courses steered are laid off for distance corresponding to the T.A.S & time on each course. The final air position is called A. From A lay in W/Velocities used by plotting directions for distances corresponding to the Wind speed & time that each W/V is used, this position is B. then calculation error is B – X. X being proposed terminal point of flight. From A lay in W/V as above, this point is called C. BC is then wind change error. Plot actual posn of A/C on E.T.A. (D) DC is then other error. DX is final error.
[underlined] points to be noted. [/underlined]
1/.
Air Speed used must be T.A.S. i.e. check comparison of I.A.S.
2/. Time must be accurately noted.
3/ Errors are determined by measurement of distances on the plot, these errors are then expressed as a percentage of the total air distance flown, in order to provide a standard to compare navigation.
[underlined] Results of Analysis. [/underlined]
1/. It provides a standard of accuracy that can be relied on by a particular crew, this being an average of the acumulation [sic] errors on a number of flights.
2/. It shows any particular error which it may
[page break]
be possible to eliminate by further practice on the part of navigator & pilot ie inability to calculate W/V’s or steer courses.
[underlined] Accepted Standard of accuracy for A/C of Reconnaisance [sic] Type (ie Anson). [/underlined]
[table]
[diagram]
[page break]
[underlined] RUNNING FIX. BY Co & A.S. [/underlined]
Bomber Command method.
The advantage of this method is that it can be used to give an accurate running fix when TRACK & G/S are either unknown or not known with sufficient accuracy to give a good fix. i.e. when flying over the sea & unable to check drift. Whilst flying in or above cloud, while flying on a dark night. On these occasions track & g/s would not be known accurately, but the CO & a/s would be known.
[underlined] NOTE. [/underlined]
THIS METHOD CAN ONLY BE USED IF THERE HAS BEEN NO ALTERATION OF COURSE OR T.A.S SINCE LAST FIX OR PIN POINT.
CONSTRUCTION (A)
From last FIX or P.P. draw on Co (T) & mark in Air Posns for times of Posn lines (bearings) (D&E). From (A) draw any line A-B
[page break]
to cut the first Posn line at [underlined] C. [/underlined] Join D-C, through E draw a parallel to D-C to cut A-B at F. then F is the point through which to transfer 1st Posn line. If 3 posn lines are used first transfer 1st Posn line to last & then second Posn line to last.
[underlined] NOTE. [/underlined]
The accuracy of this method depends to some extent on the angle between the course & the line [underlined] AB [/underlined] which should be in the nature of 10 - 15. The D.R. track may be used as line A – B if the D – R drift is sufficiently large ie angle between Co & AB large enough.
[page break]
[diagram]
Line of radius of action can be calculated from a formula, or by putting ground speed out against ground speed home on back of computor, then looking for two numbers opposite each other on outer & inner scale the sum of which equals the duration of the flight in minutes. Point to turn is found by measuring distance calculated from G/S out and time for radius of action.
[page break]
[underlined] Radius of Action to Second or Moving Base [/underlined]
[diagram]
[page break]
[page break]
[calculations]
[page break]
[calculations]
[page break]
[calculations]
[page break]
[calculations]
[page break]
6/. Go to crew room & check up on small notices published in your absence, particularly your next standby.
[underlined] Bombing Recco [/underlined]
1/. Exact location.
2/. Layout of TARGET.
3/. Vulnerability.
4/. Damage done in previous raid.
5/. Tactical information.
a/. The visibility of the TARGET from different angles of APPROACH.
B/. Landmarks as an aid to low level attacks.
c/. Landmarks as an aid to night attack
d/. Enemy defences, fighters & A-A
e/. Met Information
[page break]
[table]
[underlined] PROCEDURE AFTER FLIGHT. [/underlined]
1/.
Aircraft met by NCO photographer. Hand to him your camera magazine & note of no of exposures & light conditions over target.
2/. Report immediately to the Ops room taking with you Forms 401 & 441 your maps & all notes made in the air.
3/. You are interrogated by S.I.O. & may here discuss verbally any assumption
4/. Sign & hand in forms 401 & 441
5/. Complete & sign photographic report, bombing report (BA), combat report (PILOT)
Collection
Citation
Ted Neale, “D R Theory Exercise Book,” IBCC Digital Archive, accessed May 13, 2021, https://ibccdigitalarchive.lincoln.ac.uk/omeka/collections/document/16371.
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