A Review of the Applications of a Horizontal Tail in the Single Main and Tailrotor Helicopter

Caldwell, A.E., Houston, S.S. and Thomson, D.G. (1985) A Review of the Applications of a Horizontal Tail in the Single Main and Tailrotor Helicopter. In: Eleventh European Rotorcraft Forum, London, UK, 10-13 Sep 1985,

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A current preoccupation of the designers of fixed-wing aircraft is the extent to which ACT might allow a reduction in tailplane size with a consequent reduction in trim drag. he role of ACT would be to compensate for the loss of stability caused by bringing the c.g. aft in order to reduce the severity of the trim requirement. The same does not apply to helicopters because they can be trimmed without a tailplane. They could dispense with the tailplane altogether and rely on feedback control to the main rotor to restore stability where necessary. There would, however, be no obvious performance benefits in doing this, and it would deprive the helicopter of the tailplane's other important function, which is to adjust the fuselage attitude. The paper enlarges on the issues presented above. The longitudinal stability and control of fixed-wing aircraft is compared and contrasted with that of helicopters, and the impact of ACT on the sizing of the horizontal tail discussed. The results of computer studies of a decoupled flight path-attitude control system for a helicopter are presented, from which it is argued that, in contrast to fixed-wing aircraft, helicopters might benefit from harnessing ACT to larger rather than smaller tailplanes than are currently employed.

Item Type:Conference Proceedings
Glasgow Author(s) Enlighten ID:Thomson, Dr Douglas and Houston, Dr Stewart
Authors: Caldwell, A.E., Houston, S.S., and Thomson, D.G.
Subjects:T Technology > TL Motor vehicles. Aeronautics. Astronautics
College/School:College of Science and Engineering > School of Engineering > Aerospace Sciences
Research Group:Aerospace Sciences

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