The low-frequency radio range, also known as the four-course radio range, LF/MF four-course radio range, A-N radio range, Adcock radio range, or commonly "the range", was the main navigation system us
Jimmy Doolittle demonstrated in 1929 that instrument flying is feasible.
Doolittle's instrument panel
The vibrating reed, developed in the 1920s, was a simple, panel-mounted instrument with "turn left-right" indicator.
Early low-frequency radio station based on crossed loop antennas; later installations used Adcock antennas for improved performance.
An airway beacon or aerial lighthouse was a rotating light assembly mounted atop a tower. These were once used extensively in the United States for visual navigation by airplane pilots along a specifi
Illustration of Airway beacon, showing designated number. In this example, for units digit "1", Morse code should be ".--" (W).
An aerial lighthouse located in Pansio, Turku, Finland
The last operational aerial lighthouse in the UK, at the RAF College main building at RAF Cranwell in Lincolnshire
Gas holder Goliath in Eindhoven (designated by the letters EH) in the 1930s