AN INVESTIGATION OF HANDLEY PAGE JETSTREAM HANDLING DURING LANDING - NONLINEAR ASPECTS

Handley Page Jetstream G-NFLC is heavily used as an airborne laboratory platform. In some circumstances, the aeroplane may be prone to pilot involved oscillations in pitch during the flare. In a previous study, linear mathematical models of the short period dynamics (estimated from flight data) were assessed against the Gibson dropback and phase rate criteria. In both cases, the aircraft response was judged to be marginally satisfactory. In this investigation, the (nonlinear) effect of inceptor dead band is taken into account. The stability of the combined linear and nonlinear elements is assessed using the Nyquist criterion, where it is shown that a pilot involved oscillation is now a distinct possibility, particularly at aft centre of gravity locations.