American fighter pilots still practice using automatic cannon, maintaining their skills with this weapon still used for air-to-air combat. Despite the increased reliability and effectiveness of air-to-air missiles, most fighter aircraft still carry a cannon. For the last half century, the most common gun for American aircraft has been the M61 20mm six barrel Gatling gun type weapon. Firing about a hundred rounds a second (and carrying enough ammo for 5-9 such one second bursts), the M61 is really only effective against targets closer than 600 meters away. Today, this usually means low, and slow, flying helicopters or fixed wing propeller driven aircraft. Once or twice a year, most American fighting pilots have gunnery practice. This is accomplished by having a target tug aircraft fly at 450-500 kilometers an hour, towing, on the end of a 500 meter cable, a 40x8 foot banner (that is about the same size as a small aircraft.) Fighters come by and try to put holes in the banner. Each target tug usually flies two sorties a day, giving 4-5 fighters an opportunity to take a shot at the banner during each sortie. The most popular way to keep track of who hit what is to have each aircraft have its ammo painted a different color so that, when the target tug lands, its easy to count how many hits each fighter got.
Modern fighters move too fast to be really effective hitting targets on the ground with cannon fire. Moreover, these expensive aircraft prefer to stay at, or above, 10,000 feet, out of the range of ground fire. But a low flying helicopter or aircraft is worth going after, and cannon is still the best weapon to use for this.
