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 me home.

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.