One of many aviation howlers that I recall is in the film on the hostage rescue at Entebbe. There were several films produced and I can't remember the actual title despite a search of IMDb but it starred Elizabeth Taylor and Kirk Douglas as parents of a hostage.
Anyway, the film shows the rescue aircraft as being C-130s which is all and good but when its time to start engines and depart the film shows a lovely shot of a radial piston start, complete with starter motor sounds, turning blades and clouds of smoke when the engine fires.
An almost generic howler is that any cockpit shot of an airliner in flight will show at least one if not both pilots with hands on controls, even in cruise.
