Effectiveness of Air Combat Flaps
The Naval Aviation Technical Arsenal's Aircraft Department conducted experiments with air combat flaps from December 1942 to February 1943. Data was obtained by recording the course of the flight with a motion picture theodolite and using a self-recording accelerometer. The experimental altitude was 2,000m. The weight of the strong wind during the experiment was 3,500kg, and the wing loading was 148.9kg/m2. When air combat flaps were used, the turning radius was reduced to 70% - 80% of the normal. There was no reduction in turning time. The diameter of the loop was reduced, and the time required to loop was also reduced.
Turning
When Kyufu approached at 148 knots and a loop was performed, the load was 3.3G, the turning radius was 180m, and the time required was 15.5 seconds.
In contrast, when approaching at 151 knots with flaps at 19 degrees, the load was 4.1G, the radius was 140m, and the time was 14.5 seconds.
Somersault
When approaching at 190.5 knots without flaps, the loop diameter was 305m with a maximum load of 3.4G. It took 11 seconds to reach the top of the loop, with a speed of 105.4 knots, a load of 1.65G, and an altitude difference; of 437m (from the point of approach to the top of the somersault). The time required to complete the loop was 23 seconds, the altitude difference was -111 m (from the approach point to the bottom of the somersault), and the speed was 184.5 knots.
In contrast, when approaching at 189.4 knots and with flaps at 19 degrees, the loop diameter was 250 m and the maximum load was 4.0 g. The time to reach the top of the loop was 9.5 seconds, the altitude difference was 398 m (from the approach point to the top of the somersault), the speed was 95.5 knots, and the load was 2.0 g. The time to complete the loop was 17.5 seconds, the altitude difference was 95 m (from the approach point to the bottom of the somersault), and the speed was 142 knots.
There was an altitude difference of 200 m between when the air combat flaps were used and when they were not used, and the speed reduction was quite large when the air combat flaps were used.
