Airline Expansion and Innovation(1927 - 1941)

Flying the Main at Night

Loading Mail Truck
National Air and Space Museum Archives

To speed up air mail service, the Post Office turned to flying the mail throughout the night-a dangerous undertaking for air mail pilots.

Night flying presented special hazards, especially getting lost. Initially, bonfires set along air routes were used to help guide pilots through the darkness. In the 1920s, the Post Office established a system of lighted airways marked by powerful rotating beacons.

Airplanes making the night runs were equipped with flares, lighted instruments, and navigation and landing lights.

Beacons Replace Bonfires

The Post Office, Army, and Commerce Department worked together to develop better navigation technologies, especially a system of lighted airways.

By the summer of 1923, air mail pilots could fly from Chicago to Cheyenne, Wyoming, guided by 289 beacons and 39 lighted landing fields. The lighting of the New York-San Francisco route was completed in 1925, and the system was soon extended to other routes.

Air Mail Movie Poster
National Air and Space Museum Archives

Hollywood later capitalized on the daring pilots who flew the mail with the movie Air Mail. Beacons posted at intervals along air routes helped keep flyers from getting lost in the dark. But flying into fog or a storm could prove more hair-raising than any fictional drama.

Airfield Floodlight
National Air and Space Museum Archives
Airfield Floodlight
National Air and Space Museum Archives

Air Route Beacon

Rotating beacons like this one, developed by the General Electric Company, were placed 16 kilometers (10 miles) apart along air mail routes. They rotated once every 10 seconds, and their powerful beams could be seen 60 kilometers (40 miles) away.

Beach, Sherman Hill
National Air and Space Museum Archives
Beacon Tower, Omaha
National Air and Space Museum Archives
Beacon, North Platte
National Air and Space Museum Archives
Beacon, Fort Crook
National Air and Space Museum Archives