A-10 Thunderbolt II "Warthog" in flight.
The slowest and most nearly perfect aircraft flown by the U.S. Air Force is the A-10 Thunderbolt II "Warthog" ground support fighter plane. This amazing aircraft entered active service during my first Army enlistment in the 1970s and remains in service now--the most beloved of USAF planes by ground troops taking enemy fire.
Most fighter aircraft are designed first to fight other aircraft in air-to-air combat, but they also can support ground troops. Anyone who has used a carving knife to serve butter, or a butter knife to carve a roast knows that specialized tools work the best.
The Warthog was designed for ground support. Nothing else. It's huge turbofan engines allow it to take off with more than 10 tons of rockets and missiles plus 1,200 rounds of cannon ammo for its legendary gun, but the Warthog has a top speed under 400mph and cruises not a lot faster than a World War II bomber.
The GAU-8/A 30mm Gatling Gun
The "Hog" was designed to "loiter" over a target, firing its cannon, dropping bombs, launching rockets and missiles, and importantly, flying just above the forward battle area, waiting for observers on the ground to identify targets.
A-10 firing its 7-barrel gun with a firing rate of 70 rounds per second.
High-performance jets from the Vietnam-era F-4 Phantom to the current F-15 Eagle and F-16 Fighting Falcon are supersonic aircraft that drop bombs and fire missiles on a target, but they can't hang around. The Phantom flew so fast that some pilots lowered their landing gear and extended flaps just to slow down over the target. The Hog can put fire on a target then circle back to the target area waiting for the next opportunity to attack, or to see who survived the first strike.
During the Vietnam War, frustration with Phantoms flying in, attacking and blazing away led to deploying the A-1 Skyraider, taking this big, propellor-driven aircraft out of semi-retirement from Korean War service. The A-1 and variants carried four 20mm cannons or eight .50 caliber machine guns and could be armed with up to four tons of rockets, bombs and missiles. Like the Hog, it could loiter. Unlike to the Hog it was not very maneuverable and vulnerable to ground fire.
Hog pilots are wrapped in a titanium pod, shielded from small arms and some larger arms. The twin-engined, twin-tailed Hog can fly with an engine failure and big chunks of the wing and tail shot off.
The Hog was slated to be replaced by the F-35 Lightning II. This Swiss Army Knife aircraft is supposed to do everything. But the F-35 costs more than $200 million each, an A-10 costs a tenth of that. The A-10 is now scheduled to begin phased retirement in 2022 and remain in service until 2040.