Air-to-Ground Communication

Ford Motor Company built 8,685 B-24 bomber airplanes at its Willow Run, Michigan, plant during World War II. At its peak in 1944, the factory produced one plane every 63 minutes. Most of the bombers left Willow Run under their own power from the on-site airport. The airport and its crew could accommodate up to 20 takeoffs per hour.

A transponder uses radio signals to identify the position, call sign, and altitude of aircraft. When the pilot pressed a button on this unit, it sent a radio signal called a "squawk code" down to ground controllers. This early transponder was used for a commercial route--its buttons are marked with several Indiana cities and signals for bad weather.

The Piccard stratosphere flight departed Ford Airport field on October 23, 1934. Spouses Jean and Jeannette Piccard ascended 10.9 miles in a metal gondola carried by a hydrogen balloon. To maintain ground communication, William Duckwitz built a radio transceiver and antenna, installing it in the "radio car" trailing the flight. Duckwitz's call sign, W8CJT, is burned into its base.

The Piccard stratosphere flight departed Ford Airport field on October 23, 1934. Spouses Jean and Jeannette Piccard ascended 10.9 miles in a metal gondola carried by a hydrogen balloon. To maintain ground communication, William Duckwitz built this radio transceiver, installing it in the "radio car" that trailed the flight. Duckwitz's call sign, W8CJT, is burned into its base.

Towards the end of WWI, the SCR-67 and SCR-68 were introduced as systems for communication between aircraft and ground radio operators. These radiotelephones could direct formation flying of aircraft, and guide airborne gunfire. George Owen Squier, Chief Signal Officer of the Army's Signal Corps, worked alongside Western Electric engineers to develop this system. In 1922, Squier developed "Wired Radio"--also known as "Muzak."

This experimental device was designed to enclose a communications antenna on an airplane. Despite having access to a sophisticated range of radio and navigation aids, pilots found that the static caused by rain and snow made such devices unreliable in the air. This housing enclosed a loop antenna on a DC3 airplane to protect it against the elements.

Airport radio navigation beacons required pilots to listen for Morse code patterns to hold the correct course--notoriously difficult during storms. In 1936, Transcontinental & Western Air introduced an anti-snow directional antenna which could be used, in high-static situations, to "home in" on airport radio signals. This loop was housed in a sleek metal enclosure, protecting it from the elements.

This device is part of the LTRA-6 aircraft radio navigation unit. Its creator Lear, Inc. was a pioneering company interested in expanding the popularity of private flight. This system was affordable and combined several low and high frequency radio navigation aids that were essential to the safe travel of small aircraft.

During his polar expeditions, Richard E. Byrd relied on navigational instruments not much changed in 200 years. Byrd's sextant measured the angle between an astronomical object -- the Sun or a star -- and the horizon. Based on the time of day it was measured, this angle was used to determine Byrd's position on a navigational chart.

Federal oversight of air traffic control began in 1938, but radar technology -- greatly improved during World War II -- was not widely implemented until the late 1950s. This computer-integrated radar scope, used at Detroit Metro Airport from 1970 to 2001, was one of the first units capable of displaying an airplane's identification number and altitude directly on the screen.