Peevy is one of the mechanics at an air field owned by Otis Bigelow. He and Cliff invested a great deal of money on a new racing plane called the Gee Bee racer. When Cliff takes it out for a test flight, it ends up getting shot down by a mobster and after the plane crashes into Bigelow's fuel truck, he ends up having to take the wrap for it along with Cliff. After he and Cliff are offered the choice to either participate in a clown act for a plane show the next day or settle in court with Bigelow, he and Cliff discover a rocket pack stashed in an old biplane, which Cliff has to fly for the clown act and after Cliff triggers the throttle on the rocket pack, it flies around the hangar. Later that night, he and Cliff saw off a wooden statue from a nearby flight school and test the rocket pack on the statue elsewhere in the valley. After the statue along with the rocket crash lands in the field, Peevy worries that the rocket will get them into more trouble than they currently were. After then head of the statue got damaged, Cliff decides they are going to need a helmet and later that night, he draws out the schematics of the rocket and builds a helmet for Cliff to use with the rocket.
The next day, when Cliff attempts to rescue Malcolm from the biplane, which runs out of gas, by using the rocket, Peevy discourages him from doing so as they have not tested it enough. After Cliff departs the airfield after rescuing Malcolm, Peevy follows him to a nearby lake and retrieves Cliff and warns him about what the helmet does while using the rocket. Later that night, he and Cliff are attacked by Lothar at their house, which later becomes a shootout by the FBI, and they end up escaping to the diner, where they hang out. Peevy recommends that they call the FBI to rid of the rocket, but then they are interrupted after Eddie Valentine's boys arrive at the diner to look for Cliff. After a rough encounter with them, Peevy discourages Cliff from using the rocket again. Having sympathy for Jenny Blake being in trouble, he helps Cliff patch up a hole in the rocket with a piece of gum. Then as Cliff takes off to the South Seas Club to get to Jenny with the rocket, someone aims a gun at Peevy after he's fallen on the floor after Cliff's take off.
Late that same night, Peevy has a meeting with Howard Hughes where he discusses some of the kinks he found with the rocket and the helmet too. Cliff arrives at the end of the meeting with the FBI and Cliff tells them about the Nazis wanting to swap Jenny for the rocket. Cliff then takes off from Howard's office and heads off to the Griffin Observatory. Later on, Peevy and Howard rescue Cliff and Jenny from the firey zeppelin with an auto gyro.
At the end of the film, when Howard Hughes delivers the new Gee Bee racer to the diner, Jenny gives him back the schematics of the rocket. Then he comes up with an idea to possibly build new model of the rocket.