xx
ri
xx


DOPPLER NAVIGATION SYSTEM IN THE U-2

William C. Reed


In 1956 I was working for General Precision Laboratory in Pleasantville, New York. Prior to this I had been an Air Force radar maintenance instructor at Keesler Field Biloxi, Ms for several years, worked on B-47 K-Bombing/Nav Systems in Wichita, Ks for Combat Crew Training, and spent two years at Sperry Gyroscope in Long Island teaching field engineers the K-Bombing System. In 1955 I conducted several factory training courses on Doppler Navigation Systems at Keesler for the Air Force.

In the spring of 1956 I was involved in a special classified demonstration of Doppler Radar Navigation for a group of Airline Executives from Pan Am and Northwest Airlines. Things did not go well at first but I managed to get things corrected and the demonstration was a success. It took all day to get to Dayton from Westchester, NY, as our ground speed in the DC-3 was about 75 Knots. With my background as an instructor I filled the time with an explanation of what was happening. Shortly after this flight I was transferred to Applications Engineering.

I had only been in the new position a few days when my supervisor became ill and I was summoned to the Vice Presidents office. There I met the VP for the first time and he asked me to prepare a Request for Proposal (RFP) for a new lightweight Doppler Radar and a track computer, which we were developing. I asked what it was for and he said he could not tell me. I asked how fast he needed it and he said “Immediately”. I advised him that the new track computer was many months from a prototype and was not available. He said he had to have something immediately. I inquired about the mission and he replied that he could not say. I asked if it was a single pilot operation and he said yes. I went to the black board and blocked out a system using an existing AN/ASN-6 Latitude & Longitude Position Computer combined with the Lightweight Doppler. The ASN-6 usually accepted an input from the aircraft’s True Airspeed System (TAS) as well as from the Doppler that measured Ground Speed & Drift Angle. When the Doppler was supplying good information the ASN-6 used the TAS input to compute wind information that could be available if the Doppler stopped supplying Ground Speed. The VP informed me that the aircraft would not have a TAS system. I suggested that we could make a small dial where the pilot could insert TAS after computing it from the Indicated Airspeed information. This would provide a back up when the Doppler was inoperative. After a devils advocate examination the VP said “OK, we will do it your way but do me one favor. Write down the reasons we are doing this so we will remember why it is this way”.

Several weeks later I was asked to come to a meeting with a company officer. There I was introduced to Dick Bissell. They informed me that Dick was with the CIA. I asked what that was and they informed me that it was our new Intelligence Agency. I was then told that I had been selected to be the only liaison with Lockheed’s Skunk Works on a new program for a high altitude aircraft that was going to over fly the Soviet Union. I was told not to tell anyone about the project. The racks for the system would be delivered to our VP’s garage and returned to Lockheed with the boxes in place. Every drawing that went to Lockheed was to be checked by me and would not be accepted by Lockheed if it did not have my signature.

I coordinated with Lockheed in Burbank on power, radome, wiring, etc. and the first system was completed a short time thereafter. I frequently had meetings with the CIA in Washington during this period at various locations, as Langley had not been completed. I was therefore not surprised to be told to go to a remote corner of Burbank Airport and wait to be let in a gate. After waiting a short time a car drove up and opened the gate and waived me through. The dirt road ended at an old GI building and I went inside. No one asked me who I was. I just remained quiet and after some time was told to get onboard the C-54 outside the building. We flew for a while and landed at the Ranch. There they checked our credentials.

The first test of our system was scheduled for the following day.

The next morning I met the test pilot from Lockheed and we chatted about the system during his preflight conditioning. The test flight was a short run to a position in South Los Angeles that we had selected. Everything worked well during the test.

I do not recall how many of these systems we provided but I always believed they were to be in the aircraft that would over fly the Soviets. The CIA seemed satisfied that all was well and I worked with them on quite a few other aircraft programs during the 50’s & 60’s.

I returned to the Ranch on other occasions for discussions but do not remember specifics. I do recall seeing one of the U-2’s that had reportedly spun in from altitude after the pilot lost his oxygen. It was in a hanger for examination.

I do remember being told to go to a barn in a cotton field near Bakersfield. Upon arrival I learned that Lockheed had moved the U-2 operations there. I was asked what was the maximum altitude our Frequency Tracker Unit would work. I advised them that 44,000 feet was the absolute limit as we had tested it in the altitude chamber. The engineers advised me that they had a different payload for an aircraft and that our Frequency Tracker would have to go to non-pressurized area. I asked them if they could “Bag it” as I had seen them do for other equipment. They said, “ yes, but you require cooling air (Blower in rear of unit).” I asked if they could run hoses between the pressure area and the bag. This would essentially extend the pressurized area. They said that might work. It was about 5:00pm. I left for my hotel and returned the next morning. The unit in question was a large “full ATR” box with over 200 wires and cables in the rear as well as the cooling connectors. Knowing how competent these Lockheed Engineers were, I fully expected to see the entire plan on drawings. What blew me away was that the two engineers said, “It works great, we electrically tested it an hour ago”. I was in the aerospace electronics industry for over 40 years and worked with every aircraft manufacturer in the free world. I have never seen a group of more competent people than that bunch at Lockheed. Talk about a CAN DO attitude!!

We understood at the time that Latitude & Longitude was not an easy navigation solution for a single pilot. What was really needed was a “Track Computer” which would provide the pilot with simple left right and distance to go information. That was under development at the time and would eventually be available as the AN/ASN-25 Dual Track Computer and would be used in PACAF’s F-100’s and many other applications. It is unfortunate that it was not ready for the U-2.

The PC-212 Doppler radar in the U-2 would eventually become the AN/APN-102. This system just provided Ground Speed & Drift Angle with an accuracy of 0.2% of actual speed. The Ground Speed & Drift Indicator was located on the lower left of the instrument panel. The control box and the ASN-6 were located on the side panel along with the dial for inserting True Airspeed. These could not have been easy for the pilot to use but space was at a premium. I do not recall if the Lat/Long information from the ASN-6 was sent to the Perkin Elmer camera’s to annotate film as was often done in recon aircraft.

At the same time as I was involved with the U-2, I was liaison with Martin Aircraft on the B-57D. This was an USAF program to achieve high altitude operations. I was at Turner AFB for the initial flight test of the Doppler System. We were communicating with the pilot as he climbed to an altitude in the vicinity of 60,000 feet. The pilot was reporting Ground Speed & Drift angle at 1000-foot intervals when he suddenly said, “It stopped working as speed decreased by more than 100 knots”. I requested that he go back down 1000 feet, which he did. He then reported that the speed was working again. I requested that he go back up 1000 feet and he did. He again reported that it had suddenly dropped 100 knots. The Colonel in charge took the mike and told the pilot that they had always known that there were jet streams up there and now they had something that would tell them what was happening. I later asked the CIA why the B-57D program was continuing since the U-2 was already operational above 70,000. His reply was security. If they cancelled the program it would send a message that something else was already working.

The Doppler radar systems in most of the world’s aircraft were eventually replaced by Inertial Systems and still later by GPS. Having been involved in this early technology I am amazed today that I can know and see on a color map where I am in my car with an accuracy of 8 feet.

I traveled the world in commercial airplanes for 40 years flying as much as 150,000 miles per year. As tiring as that was for me, especially trips to Australia, Singapore, Hong Kong, etc. I never forgot what it must have been like for those U-2 pilots. I was traveling in first class much of the time and could walk around, sleep, watch movies, eat, and not worry about someone shooting at me. They spent over an hour laced up and on Oxygen before launch, and then strapped in that tiny cockpit for up to 9 hours. I have the greatest admiration of every one of them that entered that dangerous realm on the edge of space. It was certainly dangerous enough without someone trying to shoot them down. My hat is off for all of them and especially those who made the ultimate sacrifice. They are truly heroes of the cold war.

In late 1959 or early 1960 Dick Bissell showed me a photo taken with the U-2 camera. He asked me what I saw. I examined the photo and after a few seconds replied that there was an aircraft pointed at the camera. He said look again. I did and after a more complete examination I replied, “my god there is a missile between the aircraft and the camera”. At this Bissell said, “They are really trying and we’re going to have to stop this stuff soon”. It wasn’t soon enough for Powers.