1. In accordance with instruction contained in Air Ministry letter reference S.5217/DAT dated 31.7.44, tactical trials have been carried out by this Unit on aircraft No. TP.814. Tactical comparisons have been made with the Spitfire IX, Spitfire XIV, Mustang III and Tempest V. Prolonged unserviceability of the Me.109 prevented earlier completion of the trials. Unfortunately the aircraft crashed towards the end of the trial before check comparison had been carried out with the Tempest V. The report therefore includes the figures from a previous trial between the Tempest and a Me.109G flown by a pilot of 1426 Enemy Aircraft Flight.
BRIEF DESCRIPTION OF THE AIRCRAFT
2. The Me.109G/6 is a small low wing, single seater, single engined, short range fighter, with fittings under the fuselage to enable it to carry a jettisonable fuel tank. A 250 K.G. bomb may be carried under the fuselage in place of the fuel tank. The undercarriage is fully retractable and the tail wheel partially retractable. This aircraft has a re-designed fin and rudder which is approximately 1 ½ square feet larger in area than those fitted to earlier Marks.
3. The power unit is a DB.605A-1 engine which develops approximately 1550 h.p. at 22,000 feet.
4. The armament consists of 2 x 13 m.m. M.G.’s mounted above the engine, 1 x M.G. 151/20 m.m. cannon firing through the airscrew hub, and 2 x M.G. 151/20 m.m. cannon in under-wing gondolas.
5. The all-up weight of the aircraft with full war load including pilot is approximately 7,488 lbs, and the wing loading is 43.6 lbs/sq.ft.
6. The cockpit is fully enclosed and rather narrow and cramped for a pilot of more than average size.
7. The instruments are very conveniently positioned and superfluous instruments and controls have been eliminated. The usual flying instruments are installed and the combination of the Artificial Horizon and Turn & Bank Indicator is a useful feature. The engine instruments are orthodox with the permissible limits marked on the dials.
8. Switches controlling the operation of the undercarriage are situated on the port side, as are also the flap and tail incidence control wheels. Electrical and mechanical indicators are provided for the undercarriage. The flaps are operated mechanically by moving the outer of the two wheels on the port side of the pilots seat. The inner wheel controls the tail incidence which registers on a gauge. The position of the flaps is indicated by lines painted on the actual flap on the port wing.
9. Engine revs and boost are interconnected and are operated under normal conditions by the throttle control. Provision is made however for independent operation of engine revs by a switch installed below the throttle quadrant. Revs may then be controlled by a two-way pivot switch attached to the top of the throttle lever. This should only be used in the event of failure of the Constant Speed Unit.
10. This aircraft has the old type canopy (see photographs at Appendix ‘A’) which is poor and considerably restricts vision to the rear and above. The forward view is spoiled by the gun magazine bulges on the engine cowling and the thickness of the metal fram of the windscreen. Another factor which makes it practically impossible to see behind, is the cramped position in the cockpit. To sum up the view all round is restricted as compared with the latest Allied types. The cockpit cover may be jettisoned by use of a lever on the port side of the cockpit.
11. The rudder is fairly heavy but not uncomfortably so. As there is no rudder trimming device, it is necessary to apply right rudder for take-off and left rudder at high speeds. The ailerons become increasingly stiff with the increase in speed especially at speeds in excess of 350 I.A.S. At speed below 180 I.A.S. the ailerons are not positive and as the stall is approached they are almost non-effective. The elevators also become increasingly difficult to operate as the speed increases. Above 350 I.A.S. this unpleasantness is accentuated as the elevator trim is practically impossible to operate.
12. The aircraft is not particularly nose heavy. The forward view is very poor and this necessitates extreme care when taxying in the vicinity of other aircraft or obstacles. The brakes are positive but the tail wheel does not caster easily and sharp turns on the ground are difficult. At all times when the engine is run at low revs acute discomfort is felt due to fumes in the cockpit.
13. Unless taking off directly into the wind, the aircraft has a strong tendency to swing into the wind and the throttle must be opened slowly. The tail wheel locking device on this aircraft has been disconnected and this increases the tendency to swing. When taking off directly into the wind however, there is no difficulty in maintaining control.
14. Low flying is not very pleasant chiefly due to the poor forward view.
TACTICAL COMPARISON WITH SPITFIRE LF.IX
15. Formation flying presents no difficulties.
Range and Endurance
16. See Table at Appendix 'B'
17. The Me.109 was compared with a Spitfire LF.IX for speed and all-round manoeuvrability at heights up to 25,000 feet.
Up to 16,000 feet the Spitfire holds a slight advantage when using 18 lb. boost, from 16,000 to 20,000 feet the Me.109 gains slightly in speed,
and at heights above 20,000 feet the Spitfire again leads in speed to the extent of approximately 7 m.p.h.
When 25 lbs.boost is employed in the Spitfire it is about 25 m.p.h. faster at heights below 15,000 feet and 7 m.p.h. faster at heights in excess of 15,000 feet.
18. The climb of the Spitfire is superior to that of the Me.109 at all heights.
It has a particularly marked advantage below 13,000 feet using 18 lbs.boost, and this is naturally more pronounced when using 25 lbs. boost.
When both aircraft are pulled up into a climb from a dive, the performance is almost identical, but when climbing speed is reached the Spitfire slowly pulls away.
19. Comparitive dives between the two aircraft have shown that the Me.109 can leave the Spitfire without any difficulty.
20. The manoeuvrability of the Spitfire IX in this respect is greatly superior to that of the Me.109 and it easily out-turns the Me.109 in either direction at all speeds.
Rate of Roll
21. Here again the Spitfire has a marked advantage at all speeds.
TACTICAL COMPARISON WITH SPITFIRE XIV USING 18 LBS. BOOST
22. The Me.109G has an inferior performance to the Spitfire in all respects with the exception of acceleration in a dive and the slight advantage in speed
which it possesses at heights between 16,000 and 20,000 feet.
Range and Endurance
23. See Table at Appendix 'B'
24. The Me.109 was compared with a fully operational Spitfire XIV and it was found that the Spitfire
possessed an advantage in speed of 25 m.p.h. at heights up to 16,000 feet (the rated altitude of the Me.109),
at which height the advantage was reduced to 10 m.p.h.
Above 16,000 feet the advantage of the Spitfire XIV increases progressively with altitude, being 50 m.p.h faster at 30,000 feet.
25. When both aircraft are at 16,000 feet (the rated altitude of the Me.109), there is little to choose between the climbing performance of the two aircraft,
but at all other heights the Spitfire has a very pronounced advantage in rate of climb.
When both aircraft are put into a dive with engine throttled back and then put into the climbing attitude their rate of climb is identical, but when using maximum power in the dive and subsequent climb
the Spitfire very easily leaves the Me.109 behind.
26. Comparitive dives show that the Me.109 possesses a slight initial advantage, but this advantage is lost at speeds in excess of 380 I.A.S.
27. The Spitfire has no difficulty in out-turning the Me.109 in either direction,
but this advantage is more marked when turning to the right, this being due to the greater power of the Griffon engine at full throttle
and further by the fact that the airscrews are revolving in opposite directions.
Rate of Roll
28. In the rolling plane the Spitfire again is superior at all speeds.
TACTICAL COMPARISON WITH TEMPEST V USING 9 LBS. BOOST
29. In every aspect of performance the Spitfire is superior.
Range and Endurance
30. See Table at Appendix 'B'
31. The Tempest possesses an advantage of 40-50 m.p.h. at heights below 20,000 feet, but at heights in excess of 20,000 feet the advantage possessed by the Tempest rapidly diminishes.
32. The climb of the Me.109 is superior to that of the Tempest at all heights, but this advantage is not pronounced at heights below 5,000 feet. When both aircraft commenced a dive at the same speed and are then put into climbing attitude, the Tempest is slightly superior, but providing the Tempest possesses the initial advantage in speed, it has no difficulty in holding it providing the speed is kept in excess of 250 m.ph.
33. Comparative dives between these aircraft show that the Tempest will pull away from the Me.109. This is not so marked in the early stages of the dive, but in a prolonged decent the Tempest is greatly superior.
34. It was found that in this aspect of manoeuvrability the Tempest was slightly superior to the Me.109.
Rate of Roll
35. At speeds below 350 I.A.S. there is practically nothing to choose between the two aircraft, but when this speed is exceeded the Tempest can out-manoeuvre the Me.109 by making a quick change of bank and direction.
TACTICAL COMPARISON WITH THE MUSTANG III USING 18 LBS. BOOST
36. The manoeuvrability of the Tempest is better than that of the Me.109, except when the aircraft are climbed steeply at low speed.
Range and Endurance
37. In view of the fuel capacity of the Mustang III, the Me.109 is obviously at a great disadvantage as far as range and endurance are concerned.
38. The comparison between the Mustang and the Me.109 found that the Mustang possesses the advantage in speed even at 16,000 feet (the rated altitude of the Me.109). At this height the Mustang was approximately 30 m.p.h. faster than the Me.109 and at 30,000 feet the advantage in speed possessed by the Mustang increased to 50 m.p.h.
39. The Me.109 has a slightly better rate of climb up to 20,000 feet, but between 20,000 and 25,000 feet the Mustang has a very slight advantage. When the aircraft are dived and subsequently climbed there is very little to choose between their performance.
40. The comparison of the respective merits of the two aircraft in dives proved that the Me.109 is steadily out-dived by the Mustang III and as the dive is prolonged the Mustang gains appreciably.
41. Here again the Mustang has no difficulty at all in out-turning the Me.109 in either direction.
Rate of Roll
42. The rate of roll of both aircraft is almost identical.
43. From the forgoing, it is apparent that the Mustang III has a formidable advantage over the Me.109 in all respects except climb, but even this disadvantage will be cancelled if the Mustang has the initial advantage of a high speed overtaking speed.
44. The increase in the area of the fin and rudder does not appear to have made any appreciable difference in the combat qualities of this aircraft. Trials carried out by this Unit against a Me.109G fitted with the old type fin and rudder, which was flown by a pilot of 1426 Enemy Aircraft Flight, have been confirmed in every way. It is not possible to comment on any handling improvement which may have been effected because no pilot of this Unit has experience with the older type of fin and rudder.
Appendix 'A' – Photographs of Me.109G
Appendix 'B' – Range & Endurance Table.
3rd December, 1944