In the new 'Secret Projects: Flying Wings and Tailless Aircraft' book,
the author states that John Lloyd, designer of the AW.52, had hoped
the project would lead to a 'large flying wing airliner, powered by six
turbojets', but that the technical difficulties were too great.
Also, in Putnam's 'Armstrong Whitworth', it is stated that :-
"(the AW.52) would itself be but a step towards the large six-jet
airliner project being actively studied by the company..."
Thanks for the insight. What I'd like to know is whether the difficulties experienced were due to the material limitations of the time, the over-expenditure development would generate, or if they would still be as unsurmountable today as they were at the time...
From the information given in the sources I've previously quoted,
and also 'British Experimental Jet Aircraft', by Barrie Hygate, and
Barry Jones's 'British Experimental turbojet Aircraft', there were
three main problems, firstly, the degree of laminar flow achieved
was very disappointing, averaging only around 5%, compared
with up to 60% achieved in tunnel tests, secondly, the aircraft's
CLmaxwas low, even with full flap deflection, due to
the short moment arm available with the tailless configuration.
This led to high downloads on the surfaces to correct the pitching
moment at low speed. This was aggravated by the extra pitching
moment generated by the lowered flaps, effectively cancelling out
their extra lift.
Thirdly, and probably most important, the aircraft proved to be
extremely sensitive in pitch. In anything other than the smoothest
air, rapid pitching oscillations would set in, which could, and did,
become divergent. On May 26th, 1949, these pitch oscillations
developed into flutter of one of the wingtips.This rapidly spread to
the whole wing,and became so violent that the pilot abandoned
the aircraft, becoming in the process, the first pilot to use a
Martin-Baker ejection seat in an emergency.
If such an aircraft was to be built today, then artificial stability
would take care of the pitch sensiivity, modern aerodynamics
would probably increase the CLmax, however, large
scale laminar flow is, I believe, still not possible, but I'm expecting
to be corrected! ;D