Stephen Villiers Appleby (9 February 1912 – 1984) was an English pilot and a leading proponent of the Mignet Pou-du-Ciel "Flying Flea" aircraft.
After taking an interest in motorcycles and engines, he was attracted by advertisements and a book Le Sport de L'Air produced by Henri Mignet about his HM.8 Avionette monoplane.
[1][2] In early 1935, Appleby started construction of a Mignet HM.14 Flying Flea, in a shed at Heston aerodrome loaned to him by his employer, Airwork Ltd. Appleby made a main wing of 5 metres (16 ft) span, on the advice of Mignet, who was unaware that a heavier than normal engine (a water-cooled Ford 10 unit) was to be fitted.
On 24 July 1935, the Air Ministry awarded it the first ever Authorisation to Fly document, being equivalent to a UK Certificate of Airworthiness with additional conditions and limitations.
On 25 July 1935, he demonstrated the Flying Flea to the press, but force-landed it in a nearby ploughed field, where it came to rest inverted.
The Daily Express newspaper had covered the construction of Appleby's Flying Flea, and it gave £100 for the aircraft to be repaired with modifications designed by L.E.
Appleby spent the spring and summer of 1936 promoting and displaying Flying Fleas at aerodromes throughout the UK, in conjunction with appearances in local car showrooms.
Henri Mignet flew across the channel to attend the event, in a HM.18 Flea that Appleby then purchased and registered (G-AENV).
Appleby then quit flying, emigrated back to France, and was later employed by De Havilland Aircraft Company.