Westland-Hill Pterodactyl

https://en.wikipedia.org/wiki/Westland-Hill_Pterodactyl

Pterodactyl was the name given to a series of experimental tailless aircraft
designs developed by Geoffrey T. R. Hill in the 1920s and early 1930s. Named
after the genus Pterodactylus, a well-known type of Pterosaur commonly known as
the pterodactyl, all but the first were produced by Westland Aircraft Ltd after
Hill joined them.

Captain G.T.R. Hill developed the Pterodactyl series in an attempt to develop a
safer aircraft: many pilots lost their lives when their aircraft stalled, went
into a spin and flew into the ground, and Hill wanted to develop a design which
was resistant to stalling and spinning. The pioneer J. W. Dunne had previously
developed stable aircraft in the form of tailless swept wings and Hill took
Dunne's ideas as his starting point.

Helped by his wife, he constructed a prototype which was flown as a glider in
1924. The design gained official interest and in 1925 it was fitted with a 35
h.p. Bristol Cherub engine and taken to Farnborough. It was later demonstrated
to the Secretary of State for Air, Sir Samuel Hoare.

All subsequent examples were funded under Air Ministry contract and built by
Westland Aircraft, who took on Hill for this purpose. The first Westland-built
type, the Pterodactyl I, was built to Air Ministry Specification 23/26. It took
the form of a braced shoulder-wing monoplane with fully moving wingtips and a
single pusher propellor. If both tips were moved in the same way they functioned
as elevators, in opposite ways then as ailerons. It was designated the Mk. IA or
IB according to which engine was fitted. It and subsequent models flew initially
from RAF Andover, the Mk. IA flying in 1928.

The Mks II and III failed to gain Ministry acceptance.

Hill's Pterodactyl designs were all intended to handle safely without any
definite stall point, allowing reliable recovery without loss of altitude even
by inexperienced pilots. The characteristic wing was of moderately tapered and
swept planform, with reverse taper at the root to improve pilot vision.

The wing was "washed out", having a slight twist which reduced the angle of
incidence progressively towards the tips, providing a near-stationary overall
centre of pressure and ensuring that the aircraft was stable in pitch. Thus, no
horizontal stabiliser was needed and the craft was tailless, allowing the
fuselage to be relatively short.



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