LITTON - RADAR ALTIMETERS & INERTIAL NAVIGATION SYSTEMS
When I joined Litton Industries' Amecom Division in College Park, Maryland in
1963, the FAA's landing minimums at the best airports with excellent ILS (Instrument
Landing Systems) was called Category 1. This category called for at least 1/2 mile
visibility and a 200 foot ceiling. The FAA was considering reducing these minimums to
Category 2 which required 1/4 mile visibility and a 100 foot ceiling if the aircraft
was equipped with dual FAA approved radar altimeters and the pilot was
qualified. Since College Park, Maryland, was about an hour and half driving time
from my home in Virginia, I commuted to Litton in my Piper Super Cruiser airplane since the
Amecom Division was located adjacent to the College Park airport. This grass field
airport was where the Wright Brothers had taught Army Lieutenant Selfridge to
fly in 1908. In 1963 it had not changed one iota. Lt. Selfridge was the first
military aviator to be killed in an aircraft crash. The Air Force's Selfridge
Field was named after him long ago.
The Boeing Airplane Company immediately put out radar altimeter requests for quotes
for the 707 aircraft. They then started a competition between ITT Avionics (who
had a standard FM mode radar altimeter), Honeywell (who had a pulse mode radar
altimeter) and Litton (who had a Bessel mode FM radar altimeter). Litton won the
competition. It was my job to sell the world's commercial air lines the Litton
radar altimeter. We immediately ordered a new Beechcraft Baron B-55 and had it
outfitted with a Collins weather radar, Collins integrated flight system, Collins avionics
and of course dual Litton radar altimeters. While the Baron was being outfitted,
I leased a Cessna 310C as shown above and had dual Litton radar altimeters
installed. Then, I began visiting every airline in the U.S. and demonstrated the
efficiency of radar altimeters compared to barometric altimeters to the airlines'
avionics engineering departments. About two months later I received my new Beech
Baron and continued demonstrations.
All barometric altimeters by nature have a specific time lag in altitude read out.
Our radar altimeter's time lag was only a micosecond. When you are only 100 feet
above the runway and descending, 500 to 800 feet per minute, any altimeter readout
time lag can be unpleasantly fatal. This is how I managed to sell 17 air lines
the Litton radar altimeter. The first air line to buy was Pan American, then Qantas
who I signed up in Australia and the others followed. The typical Boeing 727
cockpit shown below illustrates how our radar altimeters were installed on the
pilots' instrument panel immediately adjacent to the barometric altimeters. The
pilot could set the radar altimeter to output a bell sound, gong or buzzer and
flashing light when an adjustable preset altitude above the ground was reached.
If the pilot insisted upon flying into a steep mountain side, he would have known
about two seconds before joining those in eternity.
SIDE TRIPS IN THE BEECHCRAFT BARON:
On returning to my home in Virginia from Miami, I always made it a point to
pickup a case of Jack Daniel's bourbon and Dewar's scotch whiskey at Bimini
in the Bahamas. It was only 15 minutes flying time from Miami in the Baron.
Also, a close friend and I visited every landing strip in the Bahamas which
was interesting. My best side trip was to Mexico City to ostensibly visit
Aeronaves de Mexico and then Puerto Vallarta on the west coast of Mexico for
a few days vacation. It was just like "Night of the Iguana" with Richard
Burton and Elizabeth Taylor.
In 1965 I joined Litton Industries' Guidance & Control Systems Division adjacent
to Los Angeles, California. My job was to sell the worlds' air lines the Litton
LTN-51 inertial navigation system. Since I did not wish to move my family to
California, I commuted on Trans World Air Line's out of Dulles International
Airport which was just five miles from my home in Virginia. I would leave Dulles
at 8:30 am on Monday morning and return Friday evenings at 8:30 pm. My very first
Inertial Navigation customer was American Air Lines' 707s flying the Pacific route
to Japan and Korea. The inertial navigation system was a cost effective device
since the manned navigator was no longer required on overseas flights. There are
no longer any manned navigators on any overseas airlines that I know of except
possibly Aeroflot. Even the Chinese and Korean Boeing overseas aircraft are
equipped with inertial navigators.
Litton was running a number of inertial navigation tests for the Air Force out of
Shaw Air Force Base, South Carolina in an old Lockheed Lodestar. The regular
pilot was frequently hospitalized with the DTs or a critical hangover. As such,
I was occasionally asked to fly from Virginia down to South Carolina to pilot the Lockheed
inertial test aircraft. No problem. I rented a little Commanche 400 horsepower
aircraft and got down there in 2 1/2 or 3 hours from Virginia. Also, I frequently
rented a local Cessna 310 and flew up to Litton's Canadian inertial navigation
division in Toronto. Illustrated below is the Lockheed Lodestar inertial test
aircraft. It was a real clunk compared to a Douglas DC-3. It paid off at about
105 to 110 miles an hour with the load we were carrying. You had better not be
more than six inches over the runway when it quit flying.
My Thursdays in California, about every other week, were devoted to sailplaning at
Tehahchapi, California. This is the very best sailplaning location in the world! Even
rocks thown up into the air after about 11:00 am will rise in updrafts or thermals or
convection lift. Tehahchapi is about a two hour 100 mile drive north of Los Angeles
located on the top of a pass of the Tehahchapi Mountains. The Mojave Desert lies
to the east and Bakersfield and then the pacific ocean to the west. Flying a little
Schweizer 1-26 on my very first visit, I got a tow to 2000 feet, released, and stayed up
till 7:30 pm using convection lift till darkness fell and I landed. Three highlights come
to mind about my five years of sailplane flying out of Tehahchapi on Thursdays.
1. The only time I ever got your Grandmother into a sailplane was at Tehahchapi.
We flew a Schweizer 2-32 which has the highest performance two place sailplane in
the world at that time. We soared in ridge lift for about an hour and let her
see the beautiful Tehahchipi Mountain Range in all its glory. I think she enjoyed it.
2. I tried to make a sailplane cross county flight to Reno, Nevada. Flew about a 100 miles
north and ran out of lift. YUK. Landed on a dirt road in the Mojave Desert.
Walked a 1/2 mile to a salt mine inhabited by Mexicans who spoke no English.
My three years of prep school Spanish saved my life. Walked another mile to a crank-up
phone and called Tehahchapi. Three hours later their tow plane picked me and towed
3. Our Litton Chief Inertial Navigation engineer turned out to be a fighter pilot Ace from
World War Two. He had shot down five German fighters in his P-47 Thunderbolt fighter.
Took him with me to Tehahchapi one Thursday. We flew the super-duper Schweizer
2-32 sailplane. I let him fly it from the front seat after our take off and tow up 1500 feet.
We stayed up about three hours in both convection and ridge lift. He loved it! I had made a
special friend for life.
Another fun project was occasionally visiting the Black Forest Gliderport at
Colorado Springs, Colorado where the Air Force Academy is located. After
visiting my United Air Lines' customers at their Denver Engineering Center I
would rent a car and drive down to Colorado Springs. A Super Piper Cub with a
special 200 horsepower engine would give me a tow in a Schweizer 1-26 sailplane
up to 12,000 feet altitude, a bit northeast east of Pike's Peak (elevation
14,110 feet). IF a good westerly wind was blowing it was simple to latch onto
a wave and ride it up, up just like an elevator. Even novice sailplane pilots
earned the Soaring Society of America's "Diamond" altitude gain requirement.