No 1 air observers navigation school three week examination



No 1 air observers navigation school three week examination


Time allowed 3 hours. Ten questions on mathematics, navigation and maps.


IBCC Digital Archive





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[underlined] No. 1 A.O.N.S. COURSE A. 2.
Time – 3 hours. [/underlined] Each question carries 10 marks.
Keep your answers to each [underlined] Section [/underlined] on a separate sheet of paper.

1. One pump fills a tank in 3 hours. A second pump fills it in 8 hours and a third pump empties it in 4 hours. How long will it take to fill the tank if all three pumps are working together? [inserted] 4hrs. 48 [/inserted]
2. Find the values for x and y which will satisfy the following equations:-
[equation] [inserted] x=9 y=2 [/inserted]

3. Define:- COURSE (a) True
(b) Magnetic
(c) Compass
Draw one diagram illustrating your answers (a), (b), (c), for the following values ….
True Course - 246˚
Magnetic Course - 260˚
Compass Course - 255˚

4. Sketch the conventional signs for the following on maps:-
(a) Danger Area; (b) Air Corridor; (c) Airship Hangar; (d) Airway Obstruction over 200 feet; (e) Prohibited Area.
5. Define:- Nautical Mile; Knot; Statute Mile; Vertical Interval; Horizontal equivalent.

6. S/C at 0800 from Prestwick to a position “B” which is 090˚ [inserted] 0830 [/inserted] Prestwick 40 miles, allowing for a wind 010/30 m.p.h. The A/S is 90 m.p.h. and Var. 15˚ W. What is course (M), G/S and E.T.A ?
Work this on plain paper to a scale of 1 inch to 20 miles. Draw a true meridian through Prestwick, letter your figure and state what all lines and three angles represent. Also mark lines in conventional manner.

7. Define: Inversion; Lapse Rate; Isobar; Gradient Wind.
8. You are flying at an indicated height of 8,500 feet. The average temperature between you and the ground is 20.5˚ F. What is your correct height? (Approx.) [inserted] 7,998.5 [/inserted]

9. Define: Hard Iron; Soft Iron; Isoclinal Line; Field of Force.
10. Explain [underlined] briefly [/underlined] how the values of the Earth’s Horizontal Force, and Vertical Force vary between the Equator and the Poles.


Great Britain. Royal Air Force, “No 1 air observers navigation school three week examination,” IBCC Digital Archive, accessed June 24, 2021,

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