A single heavy load airdrop and its effect on a reversible flight control system

Purpose This paper aims to investigate the addition of airdrop capability to a commuter aircraft and its consequences on the reversible flight control system. Design/methodology/approach Airdrop was modeled to include its effect on aerodynamics and flight control system. A mathematical model was also developed for the reversible longitudinal flight control system of a regional commuter aircraft using the available geometry, mass property and kinematics. The model was incorporated into a general multi‐body dynamics code and validated using existing manufacturer's data which included recorded data from flight. The airdrop simulation results showed that the flight control system is affected in two steps. In the first step, the movement of the load required a forward force by the pilot. In this step, the elevator power was a key factor and had to be increased to allow the pilot to keep the aircraft in trim position during the airdrop. In the second step, a sudden forward shift of centre of gravity required an abrupt change in the direction of applied force. The maximum allowable force and control column movement had to be checked. In the case under study, they did not impose any difficulty. Findings The result showed that a special consideration had to be taken into account when an aircraft with reversible flight control system was to be used for airdrop mission. Originality/value This paper investigates the behaviour of a reversible flight control system during airdrop operation through analysis and simulation.