The Rocketeer

In 1938 Los Angeles, two gangsters in Eddie Valentine's gang steal a rocket pack from Howard Hughes. During their escape from the authorities that ends up on an airfield, one gangster is shot to death, the getaway driver hides the rocket pack, and Stunt pilot Cliff Secord's Gee Bee racer is totaled in the resulting auto-airplane accident, crippling his career; he and airplane mechanic Peevy later find the rocket pack hidden in a biplane cockpit. Movie star Neville Sinclair had hired Valentine's gang to steal the rocket pack, and he sends his monstrous henchman Lothar to question the injured getaway driver, who tells him the rocket pack is at the airfield. Read more on Wikipedia.