Visible crew/equipment: When Wild Bill crash lands his P-40 Tomahawk in the street, then dazedly tries to "bail out", watch his parachute. A nearby explosion is supposed to catch the parachute and pull him backwards, but the 'chute doesn't react to the explosion. Instead, a line attached to the end of it pulls Wild Bill backwards.
1941 (1979)
1 visible crew/equipment mistake - chronological order
Directed by: Steven Spielberg
Starring: Christopher Lee, Dan Aykroyd, Ned Beatty, John Belushi, Lorraine Gary
Revealing mistake: When the Ferris Wheel at the theme park has broken from its mounting and is rolling down the pier, it appears to be rolling forward but rotating anti-clockwise when if it is rolling forward it should be rotating clockwise.
Colonel Akiro Mitamura: Destroy that industrial complex.
Trivia: The U-boat in 1941 was a mock-up made just for the film. It was the front half only and all scenes of the sub were shot on a sound stage water tank. The sub just rose up and down out of the water. They did have a model sub that floated in the same studio tank for the scenes with the amusement park and ferris wheel.