Trivia

Experienced, but amateur skydivers, most with several thousand jumps to their credit, were brought in from California to double for the actors. During one take, an unexpected gust of wind pulled the chute and caused one of the skydivers to be slammed into the ground, breaking his collarbone and dislocating his shoulder. Even though in great pain, he stayed in character and managed to get up and finish the scene. He was retained by Director John Frankenheimer as a consultant.

During filming at the airfield in Benton, Kansas, Director John Frankenheimer wanted to get a real, horrified reaction from the extras playing the audience, so he had a mannequin dressed like a skydiver and tied it under a helicopter, which ascended several hundred feet, then released the dummy. Most of the people hadn't noticed what had been rigged up, so when it fell, they thought it was a real person hitting the ground and he got the reaction he was looking for. One minor problem was that the pilot didn't gauge the wind accurately and the "skydiver" fell into some parked cars, narrowly missing some people and caving in the roof of an extra's car. The studio bought the car for several times what it was worth and the damaged vehicle spent the rest of the shooting behind one of the hangars.

John Phillip Law was cast as Malcolm Webson, the youngest of the three skydiving barnstormers, but had to be replaced by Scott Wilson because Law injured his wrist while filming a scene. Director John Frankenheimer wanted a close-up of him landing after a parachute jump and while in harness he was raised just out of camera range by a crane, then released to float into the shot. When he landed he fell and broke his wrist badly when he put his hand out to break his fall.

Director John Frankenheimer claimed the film did not get the same attention as his thrillers, like Seconds (1966) and The Manchurian Candidate (1962). Despite this, he would call this one of his two favorite films.

TCM occasionally plays a 15-minute-long documentary short titled The Sky Divers (1969), narrated by Wink Martindale, on the making of this film. The short is also provided on the Warner Brothers DVD, often cited as simply a "Behind-the-scenes documentary" featurette.

Amzie Strickland: as the woman seated next to Elizabeth (Deborah Kerr) at the Ladies Club meeting. With almost three hundred roles in a career that spans 1937 to 2001, it can be assumed Strickland, with just three seconds of screen time and no dialogue, had a speaking part which ended up on the cutting room floor.