Fairchild Republic A-10 Thunderbolt II
Because the Avenger fires such big bullets (exploding artillery shells 3cm wide) at such a high rate of fire (up to 40 every second) many believe it can destroy any target very easily, even tanks with thick armor such as the M1 Abrams.  However, while the bullet can go through thin metal on a car or truck, it cannot penetrate the thick metal walls of a tank.  It can only destroy them because most tanks only have thinner metal on the top to make them lighter.  If an A-10 hits this thinner armor, then destruction is more likely, but if it hits the front or sides where the armor is thicker, then the tank crew and systems will survive.