At the Edge of Space

by Milton O. Thompson

The X-15 was mated to the B-52 for the fourth time and the flight was finally made on August 22nd As all this would indicate, it was occasionally tough to get a flight off. Every once in a while we went through a series of problems like this. Thank God for a patient and thorough maintenance crew.

  The prelaunch activity went smoothly except for a loss of radar tracking by both Edwards and Beatty radars at 8 minutes to launch. Both radars reacquired track at 4 minutes to launch and the launch occurred on time. Joe got a good light and pulled back on the stick to increase angle of attack to 13 degrees. At 11 seconds after launch, he had reached the desired 2 g rotation rate and he maintained 2 g until 29 seconds after launch, when he should have reached his 48-degree climb attitude.

  At 28 seconds he was only indicating about a 40-degree climb attitude, so he quickly pulled the nose up to 48 degrees where he stabilized. At 70,000 feet altitude his altitude predictor should have read 100,000 feet. Instead, it showed 135,000 feet. It appeared that he might be going higher than planned. Joe decided to reduce his climb attitude by 4 degrees to preclude another altitude overshoot.

  At 90,000 feet altitude, his predictor was indicating 170,000 feet which again was higher than it should have been. Joe made a couple more corrections in pitch attitude and finally at 150,000 feet altitude, the prediction appeared to be agreeing with the planned forecast for that altitude. Joe planned to shut the engine down when the predictor passed through 360,000 feet, however, just before he could retard the throttle, the engine burned out. Joe checked the predictor immediately after burnout and saw that it indicated a maximum altitude of 362,000 feet.

  At burnout, Joe was passing through 176,000 feet altitude traveling at 5,600 feet per second. He then began the long coast to peak altitude. It would take almost 2 minutes to reach peak altitude after burnout. Two minutes does not sound like a lot of time, but try timing it. Just sit back in your easy chair and count off the seconds. It is almost impossible to believe that you can continue to coast up in altitude for that length of time after the engine burns out. It gives you some feel for how much energy is involved at those speeds. For comparison, when you throw a ball up in the air as hard as you can, it only coasts upward a maximum of 4 or 5 seconds. The X-15 coasted up for 120 seconds.

  The airplane would coast up another 178,000 feet during that time to peak out at 354,200 feet rather than the 362,000 feet predicted. On this flight, the engine burned an extra second, but Joe’s average climb attitude was one and one-half degrees low, so the two errors tended to average out with a slightly low peak altitude. At 330,000 feet on the way up, Joe was supposed to roll into a 45-degree left bank and hold that bank until he reached peak altitude. However, the airplane began rolling off to the right. Joe attempted to correct the drift by applying left roll control, but he got no response. He finally resorted to the left-hand manual reaction controller and managed to level the wings and then roll into his desired left bank.

  Postflight analysis indicated that one of his roll reaction control rocket lines had frozen up, preventing the rocket from firing. By going to the manual reaction controller, he commanded both left roll rockets and managed to get one to respond. He continued to use manual roll command until he reentered the atmosphere. At peak altitude, Joe pushed to a 20-degree nose-down pitch attitude to set up for the reentry. This attitude gave him an angle of attack during entry of about 25 degrees, since the flight path was about -45 degrees. Again, the automatic reaction controls failed to maintain this attitude, so Joe had to resort to manual reaction controls to keep the nose at this attitude.

  The aircraft began its plunge back toward earth picking up speed and rate of sink as it descended. On altitude flights such as these, the airplane came down at the same angle that it went up, which on this flight was 45 degrees. The aircraft also entered the atmosphere at roughly the same speed that it left the atmosphere, so as it descended through 170,000 feet it was traveling at 5,500 feet per second and descending at over 4,000 feet per second or 240,000 feet per minute. The g forces began building up very gradually as the aircraft descended through 120,000 feet and finally peaked at just over 5 g at 95,000 feet.

  By this time, the aerodynamic controls became effective and were used for control during the pullout. Joe maintained 5 g during the pullout until he came level at 70,000 feet altitude. The pullout, as Joe said, was, “One big squeeze.” He was decelerating as he was pulling out, and as a result he was subjected to a combination of eyeballs-out and eyeballs-down g forces. This combined g vector could approach 7 g acting on the pilot which again does not sound like much, but he had to maintain this g level for about 25 seconds to complete the pullout. The blood tended to pool in the pilot’s arms and legs regardless of the squeezing action of the g suit. It really hurt.

  The glide back to Edwards was uneventful, and Joe made a beautiful landing right next to the smoke flare marking the desired touchdown location. He had traveled a ground distance of 294 miles starting from a launch at Smith’s Ranch in Nevada. He had climbed almost 60 miles after launch to a peak height of 67 miles and had descended to make a perfect landing 11 minutes and 8 seconds after launch.

  Joe did not say much about the view at peak altitude on this flight, but on his previous flight to 348,000 feet, he said, “The overhead aspect is just like one of these dark velvet photographer’s cloths as far as the sky appearance, but there weren’t any specks of light shining through that I could pick out.” Joe did not necessarily wax eloquent about the view on either of these flights, but then Joe was pretty businesslike when he was flying airplanes. He would much prefer to talk about the airplane.

  Joe was the fifth pilot to leave the program. White had left six months after his record altitude flight. Rushworth and McKay were the only remaining pilots of the original group. It was time to add some new pilots. Joe Engle and I were to be the replacement pilots. We two rookies were replacing five veterans—some very big shoes to fill. For my part, I was replacing Joe Walker and Neil Armstrong. Someone must have had a lot of confidence in my abilities. I was flattered. I would be following the contrails of giants.

  THE GENESIS OF A RESEARCH PILOT

  One might wonder how an unknown pilot became involved with a famous airplane. In my case, it was a result of being in the right place at the right time. I had become aware of the NACA (National Advisory Committee for Aeronautics) and its role in flight research through Scott Crossfield. He and I were in the same naval reserve squadron in Seattle, Washington, for a brief period of time in 1950. I joined the reserve fighter squadron about six months before Scott left the squadron to move to California to begin flying for the NACA at Edwards. Over the next few years I was really impressed with the stories I heard about Scott flying experimental aircraft, particularly the rocket aircraft.

  I did not know Scott very well before he left, but I wrote to him anyway inquiring about a job as a test pilot for the NACA. Scott did not answer my letter. It was several years later that I found out Scott had a very low opinion of me. In fact, he considered me to be a dumb idiot. Scott was never one to mince words, especially in his younger days. He has mellowed over the years and I think he now considers me a friend. At least he has not called me an idiot lately. Since I did not get any encouragement from Scott, I kind of gave up trying to get a job with the NACA as a test pilot and instead worked at Boeing as an engineer after graduating from the University of Washington. I started working at Boeing as a structural test engineer, but was later transferred to flight test, since they needed flight test engineers to support tests of the new B-52 bomber.

  I enjoyed flying as a flight test engineer on the B-52, but it was a terribly demanding job. The test flights varied in duration from 4 to 8 hours and the test engineer was working nonstop from takeoff to landing. Everyone on the test team except the flight test engineer, got a break or two during a test mission. The flight test engineer was always the one individual pacing the entire flight and thus, everyone had to wait for him at one time or another during the flight. I have
never in my entire life worked so hard and so fast as I did then as a flight test engineer on the B-52. As a test engineer, if I was not taking data, I was reloading oscillographs, calculating weight and balance, managing fuel transfer, keeping a log on every event that occurred or strapping myself in and out of the damn ejection seat, because I was always having to move around that cramped cabin.

  After about 6 months of flying as a test engineer, I decided that if I was going to fly for a living, I would rather fly up front. I went to see the chief pilot about a job as a pilot. He was nice to me, but he politely informed me that I did not have much chance of being a Boeing pilot since I was a former navy pilot. Boeing built and sold airplanes to the air force. A navy pilot was not the best salesman to sell airplanes to the air force. That was my first exposure to the politics of the military-industrial complex.

  Something unusual happened next. Three engineers from the NACA at Edwards showed up at Boeing to obtain data on the structural loads being measured on the B-52. I felt this visit by the NACA engineers was strange, because I had tried to get a job with the NACA at Edwards and then had given up. Now, all of a sudden, the mountain had come to Mohammed.

  I happened to be working on the structural loads B-52 aircraft that they were interested in. They spent a few days monitoring our test operations before gathering data to take back to Edwards. One of the NACA engineers, De Beeler, was the number two man in the NACA Edwards organization. He was impressed with my work as a flight test engineer and asked if I would like to work for the NACA at Edwards. I said, “Yes, if there is a chance to eventually fly as a test pilot.” He said he could not promise anything, but he felt there was a chance. That was enough for me. I went home and told my wife that we were going to California. I made one last attempt to get a job as a Boeing pilot and, after being turned down again, I packed up and left for California.

  I arrived in California in February of 1956. I worked for the NACA at Edwards for two years as an engineer. I began flying as a research pilot for the NACA in January of 1958, just a year and a half before the first X-15 flight. I became an X-15 pilot by the process of simple elimination and succession.

  When I first began flying for the NACA, there were only five pilots at Dryden. Three were designated as X-15 pilots at the beginning of the program. That left only two of us who were not scheduled to fly it. At least two NASA pilots were needed to keep three X-15 aircraft flying. As the flight program progressed, Joe Walker moved out of the X-15 into the B-70 program and Neil Armstrong left the X-15 program to become an astronaut. That left two openings for an X-15 pilot and I was next in line. As I said previously, I was in the right place at the right time.

  As a young kid, I was very interested in airplanes, but not overwhelmed by a desire to fly. I built model airplanes by the carload and had them hanging all over my room. I could not get them to fly properly because no one had ever told me how to ballast the model properly. I became so disgusted that I would build them and then take them up to my second floor bedroom, set them on fire, toss them out the window and watch them go down in flames.

  I did talk my father into letting me fly in an open cockpit biplane and in a Ford Trimotor when I was 12 or 13. I also spent a lot of time hanging around my hometown airport at Pontiac, Michigan. I really loved to see the army airplanes that occasionally landed there, but I did not live for flying alone. I enjoyed a lot of the normal things that young boys do like hunting, fishing, and ice skating. I think the biggest adventure I had as a teenager growing up was working on my uncle’s ranch in Colorado. So to me, flying was not everything, but I did get turned on by it.

  Recruiters from the U.S. Army and the navy came to our high school in the spring of 1943 to talk to the boys in the senior class. They were looking for volunteers for aviation cadet training. About a third of the boys in the class volunteered, including a major share of the senior football players. The majority opted for the army aviation cadet program. I did too, but I was not old enough. You had to be 18. I was only 16 and would not turn 17 until just before graduation.

  The navy, on the other hand, was willing to sign me up, so I joined the naval aviation cadet training program. At that time, they had a program designated as the V-5 program for aviation cadets, which involved one year of college before entering formal flight training. It was really a good deal for a youngster who wanted to fly. I went to Detroit to take my physical and I passed with flying colors even though I was kind of a runt at that time. Surprisingly, a number of the football players flunked their physicals.

  I received orders to report for duty the following February. I had 7 months after graduation before I had to report, so I went to work on my uncle’s ranch in Colorado. I really had a ball working on the ranch because we went hunting and fishing whenever we got the urge. I would love to have stayed there and worked as a cowboy, but the war would not wait. Instead of growing spurs, I was to grow wings.

  I spent my first year in the navy at Milligan College in eastern Tennessee, cramming two years of college into one year of classes. Eastern Tennessee was beautiful, but racial segregation and hillbillies were a real shock to us midwesterners. I will never forget those hillpeople walking down from the hills in single file with the man in front and then the woman and all the kids following her. The man was usually carrying a rifle, and the woman was carrying a baby and chewing tobacco—a page out of the past.

  I was finally transferred to preflight school at Chapel Hill, North Carolina in March 1945. Preflight school was normally a 3-month school, but the war seemed to be winding down, so they extended our preflight training to 6 months. The war ended just as I graduated from preflight school in September of 1945. Every cadet was given the opportunity to get out of the navy at that time and I decided to get out, along with 95 percent of the other cadets.

  Separation processing was, however, painfully slow. After waiting two weeks to be processed, I changed my mind and decided to finish my flight training. I was immediately transferred to primary training at Norman, Oklahoma. At Norman, I learned to fly in Stearman biplanes. The navy designation for the Stearman was N2S. I will never forget taking off and landing in echelon, with a hundred other Stearmans on my wing, on those big square blacktop landing fields. The traffic congestion was unbelievable, and yet we had no midair collisions. God has to be protecting innocent fools.

  I will also never forget how cold it was in those open cockpits during an Oklahoma winter. We prayed for a temperature inversion when we took off in the morning and if we encountered one, we stayed at altitude to keep from freezing to death. Even those bulky sheepskin flying suits would not keep a person warm.

  From Norman, Oklahoma, I went to Corpus Christi, Texas, for instrument training. I flew SNJs, the navy version of the AT-6, at Cuddihy Field outside of Corpus Christi for 3 months, and was then transferred to Pensacola, Florida, for advanced training. My first training at Pensacola was in PBY flying boats. At that time, all cadets were given multiengine training in either PBYs or SNBs, the navy version of the C-45. I really enjoyed flying the PBY, although it was terribly slow and had enormous control forces. Maximum cruise speed, as I remember it, was 105 knots. In seaplanes, the real significant events are the takeoffs and the landings. Flying is just the boring interval between the takeoff and the landing. On takeoff, if we did not get the airplane up on the step, we could not get airborne. I watched PBYs ploughing through the water for miles trying to get airborne when the student had failed to yank the yoke back hard enough at the proper instant during the acceleration.

  Landing techniques varied depending on the sea state. In calm weather with smooth glassy water, the pilot simply set up a rate of descent at a speed slightly above stall and flew the airplane into the water since he could not judge height. In rough seas, he stalled the airplane before he hit the water. The thing the pilot always feared in a landing was a bounce, because this could result in severe porpoising and structural failure if proper recovery procedures were not initiated immediately. My maj
or impression from flying PBYs was that the water was hard and it was amazing how hard one of those airplanes could hit the water and still stay intact. They were fun to fly and taxi on the water, but the control forces were horrendous. Flying a PBY was like flying a seagoing ship. A throw-back to the World War I navy.

  From PBYs, I went to “Bloody Barin” Field for advanced training in SNJs. At Barin Field, we learned to fly formation, shoot gunnery, and drop bombs. This phase of training was the toughest in terms of the number of cadets washing out. The type of flying taught in this phase quickly separated the men from the boys. It also permanently separated out many of the marginal students. That is how “Bloody Barin” acquired its name.

  From Barin Field, I was transferred to Saufley Field for carrier landing training. At Saufley, we learned to fly around the pattern for hours at speeds just 3 or 4 knots above stall. We also learned the rigid discipline associated with carrier landings, wherein you put your life in the hands of someone standing on the ground or on the ship—the LSO, or landing signal officer. When he signaled that we were going too fast, we slowed down regardless of what our airspeed indicator said or how close we were to stall.

  Once the pilot was in the carrier landing pattern, he was under the LSO’s command. The pilot’s opinions or judgment were irrelevant. He obeyed the LSO’s commands without the slightest hesitation. Carrier landing training must have been patterned after the same type of training given Custer’s troopers or the cavalry in the Charge of the Light Brigade—totally rigid discipline. It worked though. That kind of training enabled a fledgling birdman to plant an airplane on what looked like a postage-stamp-size carrier deck that was bobbing around in the middle of an ocean.

  The first carrier landing obviously was the toughest, but once the pilot was convinced that the LSO knew what he was doing the carrier landings became an exhilarating challenge. I successfully completed my carrier landing qualification by making six landings on the light carrier USS Saipan. Following an unusual side trip up the canal to Houston on the carrier, we returned to Pensacola to be commissioned as ensigns and presented our wings. After two and a half years of training I became a full-fledged navy pilot.