You're probably thinking of strafing, which can be done with rockets, as well.
The aircraft mounted machine gun was at first simply a ground machine mounted for a gunner to fire. All sides in WW1 used it. The first successful machine gun fired by a pilot was the Lewis machine gun on a special mounting attached to the top wing, allowing the gun to fire over the propellor.
A cannon is a direct fire weapon as used on tanks. A machine gun is rapid fire weapon of a smaller caliber used by infantry or aircraft, and a howiitzer is artillery which uses a high angle of fire to project shells in a plunging manner on the target. In general, a cannon is 20mm or larger, a machine gun is 20mm or smaller and a howitzer is 75mm or larger.
Yes because as you can see, the gun of the AC-130 is really scary. The AC-130 is a spooky aircraft because as it fly in the air it can open fire and attack ground targets. It's gun is really freaky.
Machine guns and cannon.
Heart attack
Yes, Machine Gun Kelly died on July 18, 1954
The Metal Storm is the World's fastest machine gun. It fires 1660 bullets in every second up to 1 million rounds per minute without having someone to crank it up. The Metal Storm can be an unmanned machine gun and can open fire automatically because the computer is operating the machine gun. No other machine gun in the World can fire as fast as the metal storm at that kind of firing speed. Metal Storm is one of the fastest machine gun in the World and can fire more bullets much faster than other machine guns. Metal Storm is not an actual machine gun. It is a volley gun. See the Related Question below for a better discussion of what a real machine gun is, and which has the highest rate of fire.
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Machineguns could be set to fire at a high angle, giving long range plunging fire. That fire could be used much like artillery fire against a distant target that was the focus of an attack.
A machine gun nest is a fixed position where a machine gun crew sets up their weapon. It is generally well covered and difficult to attack all while giving the machine gun crew a good arc of fire in the desired direction. The idea is to be able to deliver fire power where you want it and to be hard to take over. A good nest can be devastating to an infantry unit if they are caught up down an alley or a bottle neck position with relatively little cover
Vickers F.B.5 Gunbus made in 1914. It made of wood and it lasted only two years in service.
Enfilade/defilade fires, direct fire, indirect fire, fire suppression, final protective lines.. there's a few different types, and it's impossible to be specific with a question worded so vaguely as this one is.