The film follows the flight of Trans-Orient-Pacific Airlines' (fictional) DC-4 taking off from Honolulu en route to San Fransisco with 17 passengers and a crew of 5. Captain John Sullivan (played by Robert Stack) and First Officer Dan Roman (played by John Wayne), both of whom battling a secret fear of flying, have a relatively uneventful take-off from Hawaii for the nearly 12-hour flight across the Pacific.
Once at cruising speed the flight deck experiences some technical malfunctions. After the flight attendant burns her hands and the pilots inspect the details of the aircraft's systems, the flight deck decides to continue to the mainland.
During this time, well-heeled passengers are relaxing and mingling in the cabin. You quickly realize that metal detectors weren't common airport technology in that time when one passenger accuses another of stealing his wife and pulls out a gun. Coincidentally, at that moment one of the propeller engines loses power and causes fuel and power loss.
As we can expect from pilots nowadays, the captain makes the decision to continue on to San Fran in the hopes they can make the "one in a thousand" chance they reach land from the "point of no return." After a few more miscalculations, the cockpit calls for a mayday when coming into the airport and the climax of the movie settles into whether or not the plane will land safely and what will happen in each of the passenger's eccentric stories.
The interior shots paint quite the picture of travel in the middle of the century, showcasing plenty of legroom, full hot meals, the lack of different classes, and passengers who "dress to fly."