The Air Force Gunsmith Shop has recently completed delivery of the 2,700 GAU-5A Aircrew Self Defense Weapon, a modified M4-style carbine designed to break down small enough to fit under most pilot ejection seats. This 5.56mm carbine can be quickly assembled in emergency situations.
The $2.6 million weapon program was developed to meet an urgent operational need to increase downed aircrew survivability.
Air Force officials announced the program in June 2018 to give pilots a more capable self-defense weapon if downed in enemy territory. In the past, aviators were armed only with a pistol and maybe a knife for protection.
A long gun firearm but with a shorter barrel than a standard rifle or musket.
Or ejector seat, a system designed to rescue the pilot or other crew of an aircraft （usually military） in an emergency.
Once clear of the aircraft, the ejection seat deploys a parachute.