The F-16 is one of the only fighter aircraft in the world to produce more thrust than the weight of the aircraft. This allows the aircraft to do really nifty things like accelerate while going straight up. This maneuver is commonly demonstrated at air shows. The pilot will "walk" his aircraft at very low speed down the runway while standing it on its tail. The force of the exhaust keeps the plane in the air in the absense of lift. When the pilot finishes his pass the only way out of this nose-up position is to accelerate straight up. This returns the flow of air over the wing to normal, allowing the F-16 to resume normal flight. If it were not for the huge jet engine, the plane would stall and crash.