Summary of Technical Trials carried out
in Middle East
1. An M.E. 109 G(tropicalised) captured in the Western Desert was allocated to No. 209 Group for performance tests, the results of which are summarized in the following paper. As the tests were not done by a recognized Experimental Establishment the figures must be treated with reserve, but the information obtained is considered of tactical value. It is hoped that tactical trials of this aircraft may be possible in the near future.
2. This aircraft is a development of the 109F-4, from which it is indistinguishable in the air. The main difference lies in the engine, that of the 109F-4 being a D.B.601E, while the Me.109G-2 has a D.B.605A. There are also several detail modifications but the airframe remains substantially the same.
3. The engine is a 12-cylinder inverted V, liquid cooled in line, with direct fuel injection. It develops 1425 h.p. for take off, and its rated altitude is 21,300 ft. It drives a V.D.M. 9-12087 three bladed metal constant speed airscrew, with electric pitch change, hand controlled or automatic. Diam. 9’ 10”.
4. The fuselage is clearly designed to be as small as possible to give maximum performance, and consequently the cockpit is rather cramped for anyone over 6 ft. tall. The controls are laid out so that the ordinary ancillary controls are worked with the left hand, the right side of the cockpit having only switch buttons. This layout, combined with automatic pitch control and automatic control of oil and water coolant flaps, simplifies the task of the pilot.
5. The rudder pedals are level with the seat, so that the pilot is in a good position to resist acceleration. All ancillary controls are convenient to reach and use.
6. Owing to the inverted engine, the top of the front cowling is narrow and the view forward on each side is reasonably good. The hood is small and has no curved surfaces. The thick Perspex panels are flat and allow a good view through them. A sliding panel on top and each side allows a clear view in bad weather. The hood is jettisonable by a red lever on the left side.
7. Consists of one curved 10 m.m. plate protecting back and top of pilots head. Three plates, the top one 8 m.m. and the lower 2.4 m.m., protect the pilots back; and a 63 m.m. bullet proof shield is set 13 m.m. behind the plexiglass windshield: a bulkhead of 30 sheets of 0.8 m.m. dural sheet is fitted to the lower 2/3 of the fuselage cross section.
8. The fuel tank is L shaped and of flexible rubber construction and is self sealing, its capacity is 85 galls. The oil tank, fitted round the reduction gear, is not self sealing and holds 8 ½ galls.
9. Is the standard Fug. 7a.
10. Standard Draiger Unit. The oxygen-air mixture is controlled by a barometric capsule up to 33,000 ft. A hand-operated button is provided for extra supply.
11. Standard Repeater unit, with the master compass fitted in the rear fuselage behind the laminated dural bulk-head.
12. Identical to the Me.109F., i.e. 2 x M.G.17 7.29 m.m. mounted above the engine and firing through the airscrew disc, and 1 M.G. 151 20 m.m. cannon mounted behind the engine and firing through the propeller hub.
13. The Elevators harden up at high speeds and retrimming is necessary, which is difficult as the twin wheel hardens up and becomes almost solid in a dive. Some force is needed on the stick, but accelerations as high as the pilot can stand can be put on.
14. The ailerons are satisfactory up to a moderate dive, and after that were used charily owing to the warning in the handbook of their weakness. Comparative combat trials are needed to complete this section.
15. Yawing in a dive is warned against. When recognized the dive is to be broken off without using force, and in a condition of yawing and turning at the same time, correction must be made with rudder and not the ailerons.
16. The diving limitations are :
|up to 10,000 ft.||466 m.p.h. I.A.S. for all types Me. 109|
|at 16,500 ft.||435 " "|
|at 23,000 ft.||357 " "|
|at 30,000 ft.||280 " "|
|at 36,000 ft.||245 " "|
17. The maximum level speeds at height of 23,000 and above and maximum air speeds appear to be identical.
18. The aeroplane tends to swing to the left towards the end of the take-off, and firm rudder is needed. The take-off is very good, so the throttle may be opened slowly, and in still air a normal pilot will be airborne in approximately 350 yds.
19. Approach should be made at 120 m.p.h. indicated. The touch down speed is between 105 – 110 m.p.h.
The minimum landing run to be expected in still air is 550 yds.
The aeroplane is rather skittish and requires some concentration to keep straight.
20. Stalling speed is 102 m.p.h. indicated with wheels and flaps down, and 112 m.p.h. with wheels and flaps up. With wheels and flaps up, the aileron controls become noticeably lighter at about 140 m.p.h. when the slots open. There is a slight and quick vibration when just approaching the stall, and with wheels and flaps up or down there is no tendency to drop a wing, while aileron control remains throughout the stall.
21. The trim is normally effective and not too sensitive, but at high diving speeds it becomes almost solid.
22. Maximum True Air Speed at 5,000 ft. - 322 m.p.h.
All these speeds were done at maximum engine power. (The Germans have cancelled maximum emergency power, apparently owing to engine failures). See Fig. 1.
23. The aircraft has a high rate of climb, while the controls are steady, and it is easy to maintain an accurate climbing speed which was found to be best at about 150 m.p.h.
24. The dive and shallow dive are very fast, and controls become heavy, but maneuverability is still sufficient at 350 m.p.h. indicated to make large deflections still possible. The handbook warns against rough movements of aileron controls during a dive, and particularly during recovery, as likely to cause a crash. Limit speed is 467 m.p.h.
25. The duration to be expected normally is one hour.
26. The complete standard German set of instruments was not fitted. Instrument flying is judged to be normal and straightforward.
27. Cockpit and exhaust shields are similar to the Me.109F. No night flying tests were carried out.
Prepared and Circulated by Air Tactics (Air Ministry)
Main Me 109 G Performance