Aircraft Gunfire Vibration: Standardization and Experience

For much of the equipment mounted on a fighter aircraft, the vibration level during gunfire is high enough above vibration due to other situations, so that, in spite of its short duration, it dominates the vibration qualification specs. It is desirable to include a simple yet reliable gunfire vibration prediction technique in the appropriate environment standards, because the relevant measured data are seldom available in the early stages of development of a new aircraft. This article describes a study on gunfire vibration prediction performed during the buildup of the aeronautical application guide of the new French military environment standard, GAM EG 13B/Air 7306. The prediction technique of MIL-STD-810D (Method 519.3) is compared in detail with previous MIL-STD-810C (Method 519.2), and the underlying concepts are checked against various measured data. Comparisons are made with gunfire vibration measurements performed on a French fighter. The findings of this study were used to elaborate the GAM EG 13B/Air 7306 gunfire vibration prediction method presented here.