[ARC5] Fwd: Re: 4-course radio ranges

[Robert Nickels]

On 2/25/2023 10:10 AM, mstangelo at comcast.net wrote:
> I wondered why it was still there and found this:

That's a very cool back-story, Mike, thanks.

In more remote areas, the airways beacons and radio ranges were manned 
by government employees who lived on-site and were responsible for 
everything from weather reporting to maintaining the navigation systems 
and powerhouse, and in some case the auxiliary landing field that was 
co-located with some radio range beacons.   These airfields were not for 
general use, but were provided so that in an emergency a pilot could 
identify a safe place to land.

Originally the radio ranges were administered by the Lighthouse Service 
of the Department of Commerce and the attendants were called Airways 
Keepers.   One such,  Mr. Edwin Cruickshank, ran radio range site #32 at 
Medicine Bow, Wyoming, along the Omaha-Salt Lake route.   Fortunately 
for us, his daughter Betty Jean, later compiled a wonderful history of 
growing up on the radio range, including many historic photos and papers 
from her father's service.    While many deal with the mundane details 
of maintaining a facility and living quarters they offer a fascinating 
insight into a different era in the history of aviation and radio.    
Her document can be downloaded from the "Attachments" section at the 
bottom of this page:

https://tinyurl.com/bdfkz79u

Below  is a brief history of the early days of aircraft navigation for 
those interested.

73, Bob W9RAN

The lone pilot dressed in a leather flight suit who sat in an open 
cockpit battling the elements to deliver the mail was romantic but 
inefficient. The Postal Service began to focus on safety and reliability 
as well as on expanding operations. It established minimum lighting 
requirements for all airmail stations: a 500-watt revolving searchlight, 
projecting a beam parallel to the ground to guide pilots; another 
searchlight projecting into the wind to show the proper approach; and 
aircraft wingtip flares for forced landings. It also prescribed that all 
landing fields should be at least 2,000 feet by 1,500 feet (610 meters 
by 457 meters) to allow plenty of room for landings. As a final safety 
device, the requirement for a searchlight to be mounted on airmail 
airplanes was appended to the Post Office's set of requirements.

The use of lighted airways allowed pilots to fly at night, but pilots 
still needed to maintain visual contact with the ground. A really useful 
air system demanded two-way voice communication and the ability to find 
out about changing weather conditions while in flight. But in 1926, 
pilots could only receive weather information and details about other 
planes in the air just before takeoff. If conditions changed while 
flying, the ground had no way to warn them. A pilot, too, had no way of 
communicating with the ground.

The Bureau of Standards began to work on two-way technology in December 
1926 at its experimental station in College Park, Maryland. By the next 
April, it had an experimental ground-to-air radiotelephone system 
operating that could communicate up to 50 miles (80 kilometers). Soon 
after, a transmitter installed at Bellefonte, Pennsylvania, on the 
transcontinental airway, successfully communicated with an airmail plane 
150 miles (241 kilometers) away.

In October 1928, the Aeronautics Branch installed a group of new radio 
stations to complement the 17 it had inherited from the Postal Service. 
It also began sending voice information to help pilots navigate, first 
by radiotelegraphy and then by teletypewriter. By the end of 1934, there 
were 68 communications stations and many pilots could request navigation 
help by two-way radio.

In 1928, the Bureau of Standards also developed a radio navigation 
beacon system, and in 1929 the Aeronautics Branch standardized a 
four-course radio range whereby pilots listened to audio signals to 
determine if they were on course. The Aeronautics Branch stepped up 
installation of four-course radio ranges, and this technology became 
standard for civil air navigation through World War II.

In September 1929, Army Lt. James H. Doolittle became the first pilot to 
use only aircraft instrument guidance to take off, fly a set course, and 
land. He used the four-course radio range and radio marker beacons to 
indicate his distance from the runway. An altimeter 
<https://www.centennialofflight.net/essay/Dictionary/avionics/DI50.htm> 
displayed his altitude, and a directional gyroscope 
<https://www.centennialofflight.net/essay/Dictionary/Gyroscope/DI105.htm> 
with artificial horizon helped him control his aircraft's orientation, 
called attitude, without seeing the ground. These technologies became 
the basis for many future developments in navigation.

The Aeronautics Branch began formal flight inspection of airway 
navigation aids in 1932. Six pilots were each responsible for about 
3,500 miles (5,633 kilometers) of federal airway 
<https://www.centennialofflight.net/essay/Dictionary/airways/DI76.htm>. 
Through 1935, the antennas for transmitting and receiving radio range 
beacons were improved and more instrument navigation tests conducted. 
September 1935 marked the first simultaneous transmission by 
radiotelephone of voice and weather information and radio beacon signals 
for navigation, and by the end of 1938, six stations were complete and 
159 were in progress.

In May 1941, the Civil Aeronautics Administration (CAA) opened its first 
ultrahigh-frequency radio range system for scheduled airline navigation, 
eventually expanding use of such equipment to 35,000 miles (56,327 
kilometers) of federal airways. In 1944, with wartime advances in radio, 
the CAA began testing a static-free, very high frequency (VHF) 
omnidirectional radio range (VOR) that allowed pilots to navigate by 
watching a dial on their instrument panel rather than by listening to 
the radio signal.

After the war ended, in 1946, the U.S. Department of Commerce took over 
200 air navigation facilities that the U.S. military had built in 68 
foreign countries. Domestically, in 1947, the CAA opened Skyway One, a 
pair of 40-mile (64-kilometer)-wide paths from Washington, D.C., to Los 
Angeles. The next year it added Skyway Two between Seattle and Boston. 
In June 1948, the CAA installed the first high-powered, low frequency, 
long-range navigation facility on Nantucket Island, Massachusetts, 
mainly to aid ocean flights. Similar 300-foot (91-meter) towers were 
built on both coasts and in Omaha.

By the middle of 1952, 45,000 miles (72,420 kilometers) of VHF and VOR 
airways, referred to as Victor airways, supplemented the 70,000 miles 
(112,654 kilometers) of federally maintained low frequency airways. The 
CAA began to shut down the low and medium frequency four course radio 
ranges.
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