Factual error: When Jimmy Stewart is almost down to the runway during the bad weather, the aircraft exterior shots show the type of cloud tops found only at high altitude, not low to the ground.
Continuity mistake: When the fire trucks are scrambled for the General's plane, watch for the open cab fire truck. It pulls fourth in line. The shot then shifts to show some sort of armored carrier go by,the shot then shifts back and the open cab fire truck is parked back by the building.
Character mistake: When Dutch is at the main gate to report for duty, he addresses an Airman as Sergeant. In the time period of this movie, an airman wearing three stripes would be an Airman 1st class.
Revealing mistake: When aircraft 5734 taxis to the runway for its first take off and comes to a stop in front of the camera for the takeoff checklist, it's clear that it is just a photo shoot and not a real take off because the jet engines still have their intake covers on. Same thing after it lands and is taxiing back to its parking location where June Allyson is waiting for Jimmy Stewart to return. The jet engine intake covers are still in place.