Prediction of the dynamic characteristics of helicopters in constrained flight

Thomson, D.G. and Bradley, R. (1990) Prediction of the dynamic characteristics of helicopters in constrained flight. Aeronautical Journal, 94(940), pp. 344-354.

Abstract

In circumstances where a pilot is forced to follow a specified flight path, such as during a landing approach or in nap-ofthe-earth conditions, it will be shown that there is an apparent modification of the helicopter's stability characteristics. This effect is identified in helicopter flight data from nap-of-theearth agility trials where oscillations are observed in the time histories of the pilot's control inputs and the vehicle's response. A technique of predicting the nature of these oscillations using a linearised helicopter mathematical model is developed. The model is inverted to give the response of the unconstrained states in terms of those strongly controlled by the need to remain on a specific flight path' Results are compared with data from flight trials and it is shown that good correlation between the period of the oscillations in the flight data and the predicted values can be obtained.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Thomson, Dr Douglas
• Authors: Thomson, D.G., and Bradley, R.
• Subjects: T Technology > TL Motor vehicles. Aeronautics. Astronautics
• College/School: College of Science and Engineering > School of Engineering > Autonomous Systems and Connectivity
• Journal Name: Aeronautical Journal
• Publisher: Cambridge University Press
• ISSN: 0001-9240
• ISSN (Online): 2059-6464