FREE-TO-ROLL STUDY OF UNCOMMANDED LATERAL MOTIONS FOR THE VENTED STRAKE F/A-18E/F

Abstract

A free-to-roll study was conducted on the lateral characteristics of a 10% scale model pre-production vented strake F/A-18E/F. This study carried out both static force and moment tests along with free-to-roll tests to determine the correlation to previous studies, assess the lateral motion, and verify free-to-roll as a viable test technique for the determination of uncommanded lateral motion potential. Static force and moment tests established correlation with previous studies. Using a figure of merit, the free-to-roll tests captured the angle of attack range over which the wing drop occurred in flight tests. Based on the equation of motion, the possible contributors to the lateral motion were: the character of the forcing function, the static lateral stability and roll damping. To determine the causal contributions three different angles of attack were analyzed, verifying the importance of free-to-roll as a viable test technique when used in conjunction with static test results.