Although the subject plane is a C-54/DC-4, several of the exterior shots use stock footage of DC-6, M-404, and CV-240 planes.
The DC-4 briefly become an American Airlines DC-6, and afterward, occasionally becomes a twin-engine Convair.
In every scene where the radio in the plane is used, the characters are directed to listen with the headsets. In the final scene, Ted Stryker does not use it to listen to Martin Treleaven's congratulations.
(at around 57 mins) The shot is facing the plane when the front wheels come down when the landing gear is lowered, and then both sets of rear wheels come down together. In the reverse shot, the front and left rear are already down, then the right hand set comes down into place.
On approach to Vancouver, the number four engine propeller has been feathered.
The first view of the instrument panel after the pilots fall ill, has most of the instruments moving around wildly and in a disconnected fashion. Since the plane was being flown by the automatic pilot, this is something done for theatrical purposes. Instruments moving like that would be seen in a wildly maneuvering aircraft or one that was crashing. For the rest of the film, views of the panel show normal gauge movements.
As the airliner settles onto the runway, sparks and flames are coming from the landing gear, but the wheels are not moving. The sparking makes it look like the tires are flat and the strut is dragging. Also the tires are very narrow for a four engine aircraft.
Although the DC-4 does have windshield wipers, they would not be running constantly during normal flight as shown. They primarily are used during takeoffs and landings, and while the plan is taxiing on the ground.
When Stryker pulls brake handle, the instrument panel moves
forward. On a real aircraft, a panel that loose would have grounded
the plane.
The yoke movements are much exaggerated compared to real life, both when the pilots fly and when the autopilot is engaged. Also, the attitude of the plane in some of the outside views doesn't tally with the cockpit view; for instance, turning and descending when the instruments show it in straight and level flight.
While the airplane is in flight, the instruments show an airspeed of 40-60 mph (which would mean the plane was in a stall) and oil and fuel pressure readings of 0 (which would mean the engines were off).
When Stryker goes to the cockpit and sees no one piloting the plane, a shot of the co-pilot's steering controls shows a string tied to the yoke to make it move.
Almost all of the shots showing emergency equipment being mobilized are sped up to almost ridiculous velocities.
When city emergency equipment is being mobilized, two men are looking at a map of the airport in the police station. It is clearly marked in a text block above the runways "Los Angeles".
When Treleaven tells Stryker to switch on the de-icers using the control by his left knee, the closeup shows Stryker's hand pressing an instrument panel light ahead of him. The de-icer controls that he should have used can be seen under his wrist to his left, on the port bulkhead.
When Dr. Baird first checks on Joey, he asks Joey to stick out his tongue, but Dr. Baird never looks down his throat, only checking his eyes.