TYPE: Experimental tandem wing aircraft

ACCOMMODATION: Pilot only

POWER PLANT: Two de Havilland Gipsy Major IC inline piston engine, rated at 140 hp each

PERFORMANCE: 102 mph

COMMENT: In 1941 the Air Ministry issued specification B.11/41 calling for a fast bomber operating from aircraft carriers. Beside high speed and bomb load main requirement was a lay out of the aircraft to give the pilot the best view possible for landing on aircraft carriers. Miles proposed a tandem wing experimental aircraft based on its M.39 design. To prove the concept Miles designed and built a 5/8th scale version, the M.39B Libulella which flew for the first time on July 1943. Flight evaluation showed no “undesirable handling” characteristics and its design coincided with interest by the authorities in unorthodox designs for large aircraft. The rear wing was higher than the forward one to avoid downwash and give ground clearance for the propellers. The M39B design had inboard flaps and outboard ailerons on the rear wing and the front wing had an auxiliary aerofoil/flap/elevator device, which could vary the wing area without changing lift coefficient. Miles continued testing, generating more flight data and submitted an improved M.39 design in early 1944. Meanwhile, the sole M.39B passed to the Royal Aircraft Establishment at Farnborough in 1944, where it was damaged and repaired after two accidents, only to be broken up with the full-sized bomber project’s cancellation (Ref.: 24).