Anticipated Spin Susceptibility Characteristics of the A-10 Aircraft

Abstract

This paper presents the results of a real-time six-degree-of-freedom computer analysis of the spin entry, spin, and recovery characteristics of the U.S. Air Force A-10 close air-support aircraft. The primary emphasis of this study was directed toward determination of the spin susceptibility of the A-10 aircraft during l-g trim and accelerated flight conditions. The computer analysis was based upon 640 wind-tunnel test hours on 1/10and 1/20scale models of the prototype A-10 aircraft at high angles of attack. The analysis approach followed guidelines of the U.S. Air Force specification, MIL-S-83691A, Stall/Post-Stall/Spin Flight Test Demonstration Requirements. The results indicated that three spin modes exist for the A-10 aircraft but that only one of these spin modes (a low angle-of-attack spin mode) could be entered with misapplied control inputs from l-g trim or accelerated flight conditons. The exception to this statement was the fully extended speedbrake configuration, where two spin modes were obtained from a l-g trim flight condition. Recoveries from all spin modes were shown to be excellent except for the high angle-of-attack spin mode, where these results were inconclusive.