5.56/7.62MM Weapons Comparative Evaluation, OH-6A Helicopter.

The 5.567.62mm Weapons Comparative Evaluation on the OH-6A helicopter was conducted at Edwards Air Force Base, California, by personnel from the US Army Aviation Systems Test Activity. The objectives of the test were to qualitatively evaluate and compare the 5.56mm and the 7.62mm automatic guns for firing accuracy and effect of the weapons firing on flight characteristics, and to quantitatively evaluate instrument panel and gun-mount vibration levels, cockpit gun-noise levels, and gun-gas levels created by weapons firing. Only minor differences were noted in firing accuracy at ranges of 500 meters or less. A pronounced loss of accuracy was noted with the 5.56mm automatic gun at ranges of 1000 meters and greater. Helicopter reactions were most apparent, for both weapons, during hover firing at a high rate of fire and were more severe with the 7.62mm automatic gun than with the 5.56mm gun. At forward airspeeds, only minor differences in flight characteristics were noted during firing of the weapons. Vibration levels of the instrument panel and gun mount were reduced significantly with installation of the 5.56mm automatic gun. Significant reductions in instrument panel vibration and cockpit noise levels were also noted for both weapons when firing with the doors on as compared to firing with the doors off. Author