Brigadier General William Mitchell tries to prove the worth of the United States Army Air Service as an independent service by sinking a battleship under restrictive conditions agreed to by Army and Navy. He disobeys their orders to limit the attack to bombs under 1,000 pounds and instead loads 2,000 pounders. With these, he proves his aircraft can sink the ex-Imperial German Navy World War I battleship , previously considered unsinkable. But his superiors are outraged.