DESIGN OF BACKUP STIFFNESS BRACKET AND INERTIAL MASS SURFACE FOR TESTING AIRCRAFT AIRBRAKE ACTUATOR

Bharath R K, Sunil N K

Abstract: All aircraft motion or maneuvers are regulated by control surfaces which are operated by the pilot from the cockpit. The flight control surfaces are classified into primary control surfaces and secondary control surfaces. Airbrake is a secondary control surface. For operating the airbrake, a linear hydraulic actuator is used. This airbrake actuator has to undergo Hydro Mechanical Oscillation (HMO) test with backup mounting and airbrake surface inertia similar to that of the aircraft. In order to ascertain the stability of operation of the actuators throughout the operating frequency range, HMO test will have to be carried out mandatorily for all airbrake actuators. The test setup for HMO consists of an equivalent airbrake surface along with the actuator and backup stiffness bracket as same as that of aircraft surface. In order to validate the backup stiffness bracket a known force is applied on the bracket and deflection due to this force is noted. The stiffness obtained thereafter shall be same as that of aircraft backup stiffness. Also the equivalent airbrake surface used during the test shall have the same weight, center of gravity and inertia as that of actual aircraft airbrakes. In this paper, the design of backup stiffness bracket for airbrake actuator is been detailed. The validation of design is done theoretically as well as by using CATIA V5 R21 CAD package

Keywords: Control Surfaces, Hydro Mechanical Oscillations (HMO), Maneuvers, Leading Edge Slat (LES).

DOI: https://doi.org/10.15623/ijret.2016.0516084