Investigation of flight dynamics of a civil aircraft with active high lift system

Abstract

In this paper ongoing research on the flight dynamic modeling and analysis of an aircraft with active high lift is presented. The considered aircraft is being designed with an aircraft multidisciplinary design and optimization tool (PrADO) and is a twin turboprop equipped with an active high lift system consisting of a Coandă surface flap whose knee is blown to enable boundary layer control. In this paper, a longitudinal model is derived from the first aerodynamic data available for this aircraft and used to make a first assessment of the flight dynamics of this aircraft configuration. In particular, the effects of the active high lift system on the trim conditions and the normal modes of the aircraft are shown, as well as a first assessment of the consequences of an active blowing system failure. A remarkable intermediate result is that with proper actions of the pilot (or the flight control system) such a failure seems to have significantly less severe consequences than initially feared.