Visible crew/equipment: In the scene on the airplane, last 1/3rd of the film, the plane crashes into the ocean and the camera shot starts bouncing up and down - you can see the airplane has no roof and the studio lights are visible.
Other mistake: In the windmill scene, the windmill reverses directions twice to signal the airplane. However when Joel McRae enters the windmill and we see the machinery it is obvious that there is no mechanism to reverse the windmill against the wind.