Preliminary report on a gust alleviator investigation on a Lancaster aircraft

Abstract

The investigation of gust alleviator effectiveness is limited to an analysis of statistical measurements of c.g. accelerations. The measured alleviation is much smaller than was initially expected and in some cases is even negative. Theoretical analysis, supported by experiment, indicates that the loss of gust alleviator effectiveness is mainly due to the large pitching moment contributed by the ailerons. The aircraft with gust alleviator in operation suffers a considerable loss of stability and calculations show that with increasing gust length alleviator effectiveness decreases and eventually becomes negative. Airframe flexibility also has some detrimental effect. The effectiveness of the alleviator in terms of wing-root bending stress alleviation is considered to be more favourable, but no experimental data are yet available.