The Miles M.8 Peregrine was a 1930s British twin-engined monoplane light transport designed by Miles Aircraft Limited. A promising design, the Peregrine never entered production as the company was preoccupied by fulfilling orders for other types to the RAF. Only two of the model were built, one prototype M.8 Peregrine, and one modified M.8A Peregrine II which was used for experimentation work at Royal Aircraft Establishment.
In the mid-1930s F. G. Miles identified a market for an eight-seat light transport. Designed by Miles, the M.8 Peregrine was his first multi-engined design, and the first with retractable undercarriage. It was a low cantilever wing, enclosed cabin monoplane of all-wood construction. The aircraft had a crew of two and was marketed as capable of being equipped with full dual controls. The fuselage was built from spruce and plywood, the cabin was long, wide and high, it could comfortably accommodate six passengers and had a further of baggage space. The wing had full split trailing edge flaps which extended under the fuselage.
The M.8 Peregrine was powered by two de Havilland Gipsy Six series II piston engines, each producing . They were fitted with de Havilland two-position variable-pitch propellers. It was equipped with two fuel tanks in each wing, giving it the range of . Sources vary about the M.8 Peregrine's speed, stating the top speed was either, and the cruising speed was either . The aircraft weighed empty, and all up, its stalling speed was without flaps and with the use of the flaps.
The prototype M.8 Peregrine first flew on 12 September 1936 with Charles Powis at the controls. It was entered in the 1936 Schlesinger Race between England and Johannesburg, but it was not ready on time. It was registered as G-AEDE, although at the beginning it carried the markings U-9. The M.8 Peregrine showed great potential and attracted much interest, but Phillips & Powis (the manufacturer) has just won a contract to build Miles Magister trainers for the RAF and no capacity existed for the manufacturing of the M.8 Peregrine, so it never entered production. The prototype was dismantled at Woodley in December 1937.
In 1938 the Royal Aircraft Establishment ordered a version of the Peregrine for experimental work. The aircraft was given the designation M.8A Peregrine II, the single example produced was registered as L6346. The M.8A Peregrine II was the first metal skinned aircraft produced by Miles, it was powered by two Menasco Buccaneer B6S engines, each producing . It had a top speed of and a cruising speed of . It was slightly heavier than the M.8 Peregrine, weighing empty, and all up.
L6346 was used by the Royal Aircraft Establishment for researching boundary layer suction. To achieve this a Ford motor driving a large vacuum pump was installed in the fuselage, the vacuum provided suction to the upper wing through specially designed, perforated wings via a series of internal ducts extending the wings length. The tests proved promising, with a marked decrease in drag and a 29% increase in rate of climb, but the outbreak of the Second World War halted the research.