When
"Slim" Lewis landed his de Havilland at Cheyenne on the night
of July 1, 1924, it triggered the end of the U.S. Air Mails nightly
railroad trip and marked the beginning of regularly scheduled night
airmail. It was a quiet undertaking. There was a demand by
businessmen, corporations and other commercial outlets that wanted same
day service, and the Post Office Department wanted it to happen.
Over
a nine month period, a necklace of rotating beacons was established
between Chicago and Cheyenne. It came to a total of 324 airway lights
for approximately 1,100 miles. The project also wired boundary lights
for terminal fields, emergency landing strips and powerful beams marking
terminals at about five major airports.
You
could say the rotating beacons were color-coded: red flashes for
dangerous hills, obstruction and unsafe terrain. Not all the beacons
were the same size. They ranged from 24 to 32 inch reflectors and put
out different candle power. They were bight enough that pilots could see
them 50 to 70 miles away, in good weather, that is.
The
beacons were also a great navigation aid in bad weather.
The
lights were calibrated so that if a pilot could see the entire light, he
was high enough to clear any obstacle. If only a portion of the light
could be seen, he was too low and had better get another hunk of
altitude under him.
The
establishment of an airway beacon and the accompanying landing strip
made the local newspapers. In cruising though copies of the local papers
of 70 to 75 years ago, the communities seemed proud to have a U.S. Air
Mail facility in their backyards.
Powering
the light systems was also very interesting. The Post Office Department
would use local electric power if it was available. Otherwise, butane
tanks were spotted near a beacon for gas firing. Another method used a
wind driven generator charging heavy duty wet cell batteries. Many of
the locations had caretakers who would daily check the operation of a
site. Where possible, a "sun switch" would automatically turn
off the light during daylight and turn it on at dusk.
Meanwhile,
24 DHs were equipped for night flying. Navigation lights were installed
on wing tips and tail, red for the left wing, green for the right wing
and white for the tail. The same lighting system is used today. Landing
lights were also installed on each wing tip. Maybe it was during this
period of aviation when the old pilots adage was born: "If you
are making an emergency landing at night and dont like what you see,
turn off your landing light."
In
1924 and 1925, the lighted airways were extended east from Chicago to
Cleveland and New York and west from Cheyenne through Rock Springs,
Wyoming, to Salt Lake City and then on to San Francisco. The last two
airway extensions were extremely difficult because of the Allegheny
Mountains on the west side and the Laramie and Wasatch Ranges of the
Rock Mountains on the west. Its tough to place an emergency field or
a beacon on a mountain top.
By
the end of 1925 at the cost of nearly $545,000, the U.S. Air Mail truly
had a day and night transcontinental airmail route covering a distance
of slightly over 2,000 miles from New York City to Salt Lake City.
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