(Cranfield Institute of Technology, 1972-06) Ward, R. E.
The potential application of advanced forms of aircraft
control to civil operation appears to be capable of being split
into two areas. First, those aircraft which are very large,
whose rotary inertia tends to reduce the effectiveness of
conventional controls. Second, those aircraft whose
specification dictates that the aeroplane be flown at very low
speed. Again conventional controls become inefficient due to
decreased aerodynamic efficiency.
The second category of aircraft has been considered in
the form of an STOL aircraft. The control problems of an STOL
aircraft with a 2000 ft runway capability (Ref.10) have been
examined. It has been found that the aircraft is unstable
and could require autostabilisation. None of the conventional
controls were satisfactory and each required augmentation.
The single strip crosswind requirement penalises the design
most heavily since this requires over half of the extra control
power necessary. The total augmentation for blowing air
amounts to an equivalent thrust of approximately 6700 lb.
This is equivalent to 11.5 per cent of the total installed
aircraft thrust.