Key point: One of the reasons the GAU-5A was chosen was for its compactness. 

While most pilots like to think of themselves as fairly detached from the brutality of warfare on the ground, they all face the very real possibility of being shot down and forced to defend themselves on the ground. For most of the twentieth century, shot down pilots could be expected to be captured and interned as POWs, so were generally armed with lightweight survival rifles or pistols. But more recently when combating extremist or terrorist groups, pilots who are shot down face being burned alive, or worse 

As a result, militaries have moved to arm their pilots with proper weapons for self-defense. In 2015, the Royal Netherlands Air Force bought B+T MP9 submachine guns for their pilots flying over ISIS territory. Some militaries were already ahead of the curve; following experiences in Chechnya most Russian pilots are armed with AKS-74U carbines in their survival kits.

But the U.S. Air Force has perhaps devised one of the most compact and effective survival rifles for a downed airman. The GAU-5A Aircrew Self Defense Weapon is a short M4 variant that incorporates a quick-detach barrel and folding pistol grip to fit within the survival kit compartment of an ACES II ejection seat.

However, the GAU-5A doesn’t use proprietary parts developed solely for the GAU-5. Perhaps due to the need to urgently field the rifles, many commercial off-the-shelf (COTS) parts were used on the GAU-5. In order to reduce the length of the pistol grip in the stored configuration, the Israeli FAB Defense AGF-43S folding pistol grip was fitted to the GAU-5A. The quick detach barrel kit is also an existing commercial product, the Cry Havoc Tactical QRB kit. Finally, a lightweight rail from Midwest industries was fitted in lieu of a standard front sight post and plastic handguard. While most modern rifles use optics, the GAU-5A uses flip-up iron sights to minimize weight and profile.

The rest of the rifle is fairly standard mil-spec, the GAU-5A appears to be built with a standard M4 lower receiver and upper receiver, with the commercial parts added on. Surprisingly, the rifle still features the three-round burst fire option. The burst cam in the rifles is notorious for making the semi-automatic trigger pull inconsistent, resulting in the Army and Marine Corps moving back to full-auto trigger groups on their AR-style rifles.

In the ACES II survival kit, the GAU-5A comes with four magazines for a total of 120 rounds, granting a shot-down pilot considerable firepower. The use of standard magazines also means that a GAU-5A armed aviator could resupply off friendly troops (though the likelihood of doing so is rather small). As the ACES II ejection seat is fitted to the A-10, F-15, F-16, F-22, B-1, and B-2, presumably, all aircrew crewing those aircraft will be armed with GAU-5As if undertaking missions over extremist-controlled territory. The F-35 does not use the ACES II seat, so it’s unknown if F-35 pilots will receive the GAU-5A.

Midwest Industries, the manufacturer of the GAU-5A rail has also released a civilian version of the weapon in pistol form. While lacking the “waffle stock” and burst trigger of the military version, the Midwest GAU-5A is a fairly faithful clone of the military weapon.

Charlie Gao studied Political and Computer Science at Grinnell College and is a frequent commentator on defense and national security issues. This piece was originally featured in December 2019 and is being republished due to reader's interest. 

Media: Wikipedia