.......Flying weight on trials = 5935 lb.

.......The aeroplane is fitted with a 2-pitch 3-blade metal airscrew and it was desired to compare the handling and the performance of the aeroplane with that of Spitfire K-9793, fitted with Browning guns and 2-pitch metal airscrew.

.......Flying weight on trials = 5925 lb.

            In accordance with Air Ministry letter, reference B.9242/39/A.D./R.D.L. dated 4th November 1939, performance trials have been carried out to compare this aeroplane with the standard Spitfire I fitted with a 2-pitch airscrew.

           N.3171 weighed in at 6,050 lbs. The 73 lb. pilot's armour found on more mature Spitfire Is was lacking. The aircraft was slightly down on power effecting top speed by about 2 mph. The engine limitations for the tests were:- Level Speeds - All-Out 5 minutes limit - 6.25 lbs./sq.inch, 3000 RPM; Climb - 6.25 lbs./sq.in. 2600 RPM Climbing 1/2 hour limit. Ironically, the day after this report was issued AP1590B/J.2-W was released, increasing the engine limitations to +12 lbs./sq.in, 3000 RPM. This allowed for an increase in speed below 10,000 feet of 28/34 mph.

.......Both the aircraft are similar externally and are fitted with bullet proof windscreen and armour plating over the tank, etc.

.......Aircraft R6774 is fitted with DH airscrew and N3171 with Rotol airscrew.

.......It will be noted that these aircraft are about 12 miles an hour down in speed against the previously tested K9793, but the relative comparison remains. This loss in speed is accounted for, by 6 miles an hour for the bullet proof windscreen and 6 miles an hour due to loss in engine power.

.......Level Speed miles per hour.

            The above tests were all carried out using 87 octane fuel with boost limited to +6.25 lbs./sq.in. Climb figures were achieved using the 2600 rpm 1/2 hour climb limit. By the Battle of Britain all operational squadrons had changed over to 100 octane fuel and the engine limits on the Spitfires had been increased to +12 lbs./sq.in. 3,000 rpm with 1/2 hour climb limit increased to 2850 - 3000 rpm.

Conclusions

.......In general flying qualities the aeroplane is inferior to both the Spitfire and the Hurricane at all speeds and in all conditions of flight. It is much inferior at speeds in excess of 250 m.p.h. and at 400 m.p.h. recovery from a dive is difficult because of the heaviness of the elevator. This heaviness of the elevator makes all manoeuvres in the looping plane above 250 m.p.h. difficult including steep climbing turns. No difference was experienced between climbing turns to the right and left. It does not possess the control which allows of good quality flying and this is particularly noticeable in acrobatics.

Conclusions

.......Take off is fairly straightforward. Landing is difficult until the pilot gets used to the aeroplane.

.......Longitudinally the aeroplane is too stable for a fighter. There is a large change in directional trim with speed. No rudder trimmer is fitted; lack of this is severely felt at high speeds, and limits a pilot's ability to turn left when diving.

.......Aileron snatching occurs as the slots open. All three controls are far too heavy at high speeds. Aerobatics are difficult.

.......The Me 109 is inferior as a fighter to the Hurricane or Spitfire. Its manoeuvrability at high speeds is seriously curtailed by the heaviness of the controls, while its high wing loading causes it to stall readily under high normal accelerations and results in a poor turning circle.

.......At 400 m.p.h a pilot, exerting all his strength, can only apply 1/5 aileron, thereby banking 45 deg. in about 4 secs. From the results Kb2 for the Me 109 ailerons were estimated to be -0.145.

.......The minimum radius of turn without height loss at 12,000 ft., full throttle, is calculated as 885 ft. on the Me 109 compared with 696 ft. on the Spitfire.