The Triumph of Technology

Improvements in aircraft and aviation technology played a key role in revitalizing the struggling airline industry.

The mid-1930s were a difficult time for airlines. The federal government had broken up the large companies that had dominated the aviation industry and had cut its subsidies to airlines. Air transportation regulation was in a state of confusion.

To survive in these challenging times, airlines needed bigger, better, and faster airplanes that could profitably fly passengers as well as mail. New navigation and communications equipment was also required to enhance safety and efficiency. The aviation industry responded. By the late 1930s, the first modern, high-performance airliners were taking to the air.

The government provided bonuses to airlines if their aircraft could fly at night or had multiple engines, two-way radios, and other equipment that promoted safety and speed. The first aircraft produced under these terms was the Boeing 247 in 1933, the world's first modern airliner. It could carry 10 passengers, fly 50 percent faster than the Ford Tri-Motor, and cross the country in less than 20 hours.
© The Boeing Company

T.W.A. needed an airplane to compete with United's new Boeing 247s. Douglas Aircraft responded with the DC-1, which was faster and more comfortable and could carry 12 passengers. Stretched to seat 14 and redesignated the DC-2, it easily surpassed its competition. Douglas went on to dominate airliner production until the jet age.

At the request of American Airlines, Douglas created a larger version of the DC-2 with sleeping berths, the Douglas Sleeper Transport. The daytime version became the famous DC-3. The 21-passenger DC-3 became the first airliner that could make a profit without subsidy, and it helped airlines survive cutbacks in government assistance. The remarkable aircraft took less than 16 hours to fly from Los Angeles to New York, and its sleeping accommodations made the flight quite bearable. Even with sleeper service, ticket prices remained fixed at $160 one way and $288 round trip.

The Boeing 307 Stratoliner was the world's first pressurized airliner. While other airliners flew no higher than about 3,000 meters (10,000 feet), the Stratoliner could cruise at 7,500 meters (25,000 feet). By ascending "above the weather," it could fly faster and more efficiently and provide its 33 passengers a smoother and quieter ride.

Because of the onset of World War II and the development of improved designs, only 10 Stratoliners were built. One, Pan American's Clipper Flying Cloud, is displayed at the Museum's Steven F. Udvar-Hazy Center.

"Flying the Beam" Board Game

To exploit air travel's popularity and to explain the new radio range system in an easily understood manner, Parker Brothers introduced "Flying the Beam" in 1941. The object of the game was to be the first to safely land at the airport using radio range navigation. Playing pieces were rubber DC-3s.
The game board graphically shows how the system worked:

• A radio beacon sent out signals in a pattern of Morse code A's (dot-dash) and N's (dash-dot).
• Where the signals intersected, they combined to produce a continuous tone, which a pilot could follow toward the radio beacon.
• If the aircraft strayed from the center of the beam, the signal for either an "A" or "N" alerted the pilot that he had strayed off course.
• The exact location of the range beacon was identified by a "cone of silence."

Gift of Frank Youngquist

Radio Transmitter

This was the first lightweight radio transmitter built for use on aircraft. It featured a loop antenna, which could be turned to find the signal direction. It supplanted traditional visual dead reckoning navigation methods.

Designed and built by Hugo Leuteritz of Pan American, the transmitter enabled aircraft to navigate accurately along Pan Am's first route, between Key West, Florida, and Havana, Cuba, in 1928. Leuteritz designed other devices that allowed Pan American aircraft to navigate safely throughout the Caribbean and across the Pacific and Atlantic.
Gift of Juan T. Trippe

Automatic Direction Finder

Developed by the Sperry Gyroscope Company, automatic direction finders (ADF) were first installed on aircraft in the mid-1930s. They replaced the existing four-course radio range system. Displayed here are the control unit and indicator and the loop antenna in its streamlined housing.

The ADF locates known stationary radio transmitters and displays the radio's location relative to the aircraft. This was a much more flexible and accurate system, as aircraft no longer had to fly in one of four radio courses. It also led to instrument approaches for landing, which helped pilots locate runways at night and in bad weather. Most aircraft built in the late 1930s and 1940s, including the Douglas DC-3 above, were equipped with ADF, with its distinctive "football" antenna housing.
Gift of Charles L. Neumann

ARC Model D Receiver

Designed by the Aircraft Radio Corporation in 1929, the ARC Model D was the first commercial navigation receiver. It pioneered the use of the four-course radio range system.
Gift of the Cessna Aircraft Company