What aircraft is built around its gun?

The Fairchild Republic A-10 Thunderbolt II is a single seat, twin-engine, straight wing jet aircraft developed by Fairchild-Republic for the United States Air Force. Its official name comes from the Republic P-47 Thunderbolt, a fighter particularly effective at close air support. The A-10 is more commonly known by its nicknames "Warthog" or "Hog". The A-10 was designed for close-in support of ground troops, close air support, providing quick-action support for troops against helicopters, vehicles, and ground troops. It entered service in 1976 and is the only production-built aircraft that has served in the USAF that was designed solely for CAS. Its secondary mission is to provide forward air controller - airborne (FAC-A) support, by directing other aircraft in attacks on ground targets. Aircraft used primarily in this role are designated OA-10.

The A-10 was intended to improve on the performance of the A-1 Skyraider and its poor firepower. The A-10 was designed around the 30 mm GAU-8 Avenger rotary cannon that is its primary armament. Its airframe was designed for durability, with measures such as 1,200 pounds (540 kg) of titanium armor to protect the cockpit and aircraft systems, enabling it to absorb a significant amount of damage and continue flying. Its short takeoff and landing capability permits operation from airstrips close to the front lines, and its simple design enables maintenance with minimal facilities.