Radio Navigation Aids
Before the world could have reliable airlines, overnight shipping, and all weather fighters, researchers and inventors had to develop a system for pilots to navigate and land their aircraft without seeing the world around them. Until a pilot could safely fly at night, in fog, or other poor weather, flight also could not compete with the railroads or trucks. From 1918-1934, the National Bureau of Standards (NBS), the US Navy, the Post Office, and other government and private organizations regularly used College Park Airport to design and test “blind flight” systems. Their work is part of the foundation of the modern Instrument Landing System still used today.
When the Air Commerce Act of 1926 dramatically increased the federal government’s role in developing and regulating aviation, National Bureau of Standards (NBS) officials became responsible to lead specific areas of aeronautical research, including developing radio aids to navigation. That summer, NBS started developing College Park as one of its field sites. They soon erected a 70-foot wooden tower supporting two antennas and a 500-watt radio transmitter. Early success came in 1927, when NBS tested a "vibrating reed" visual radio beacon indicator. In this system, the ground transmitter emitted two radio signals for the plane to receive. If the pilot was in between the two signals, the two reeds on the airplane would appear the same length. When the plane was too far to the left or right to find the airfield, the corresponding reed would appear longer. However, the system was not accurate enough, did not respond fast enough to changes in direction, and was too heavy for commercial aircraft.
In 1931, a brand-new Curtiss Fledgling J-1 Special, a 2-place open cockpit biplane trainer, was acquired for blind flying tests. It had a collapsible hood that could cover the pilot's cockpit for blind flying tests without obstructing the view of the backup pilot. On September 5, 1931, Marshall Boggs used this plane to complete the first blind landing at College Park, with James L. Kinney as check pilot. While accuracy was improving, the system was very sensitive and was only effective in good weather (no wind, no turbulent air, no radio static), the opposite of when instruments were needed.
In late 1933, financial cutbacks dictated by the Great Depression ended the government organized development. However, several former NBS employees then established the Washington Institute of Technology (WIT) to continue developing radio navigation at College Park. WIT then produced blind flying instruments for the US Navy to test. On May 1, 1934, Navy Lt. Frank Akers took off from Anacostia Naval Air Station in a Berliner-Joyce OJ-2, and successfully landed at College Park using only the WIT instruments. A little over a year later, on July 30, 1935, Akers used similar equipment to land on the aircraft carrier USS Langley, while it was underway off the coast of San Diego. Despite these successful tests, the technology was not yet accurate enough for regular aircraft carrier operations. However, it was useful for Navy seaplanes.
Although the Navy didn’t purchase the system, WIT officials created the Air-Track Corporation of College Park to sell the landing equipment to commercial airports. Pittsburgh, PA, officials bought and installed the system leading to the first blind landing of a passenger-carrying flight on January 28, 1938. Unfortunately, pilots never trusted the system enough to encourage airlines and airports to invest in this system.