 FACT: When Frank goes to his carriers flight deck to halt the  launch of the mail plane, he is wearing a ships ballcap. After  packing, he returns to the flight deck wearing a combination cap. In  fact, neither hat is permitted on the flight deck during flight  operations, as they are easily sucked into a jet engine intake,  causing foreign object damage. Further, no person is permitted on  the flight deck without the cranial helmet, goggles, and hearing  protection that we see the catapult launch officer wearing.