Tests on the hurricane L.1696 in the 24-ft wind tunnel

Abstract

Tests on a Hurricane in the 24-ft Wind Tunnel at the Royal Aircraft Establishment were required to find if any simple modifications could be made which would reduce its drag. Measurements were made of :- (1) Leak drag. (2) Drag of miscellaneous excrescences. (3) Cooling drag. (4) Drag of the tail unit. The tests showed that the leak drag plus the drag due to the control gaps was 13 per cent of the total prone drag of the aircraft. Of this leak drag only one-third could be eliminated by methods which could be incorporated in production aircraft without serious modification. This emphasises the importance of eliminating leaks in the design stage. The drag of the cooling system was reasonably low, and tail-fuselage interference was small.