Once the cockpit checkout was complete, the cockpit canopy was closed, the crew chief, Larry Barnett, gave me a salute and the servicing and access equipment was cleared away from the X-15 and the B-52. Next came B-52 engine start and checkout of the various B-52 systems, and then the B-52 entry hatch was closed and we were ready to taxi. The taxi out to the runway for takeoff was another major event. A convoy of about ten vehicles trailed the B-52 out to the runway and a chase aircraft taxied out with it. A rescue helicopter took off to survey the runway before the B-52 takeoff. It then took up a hover position alongside the B-52, preparing to follow it down the runway on takeoff. Just prior to takeoff, the X-15 crew pulled the safety pins on the X-15 launch hooks. At that point we were armed and ready to go.
It was very unusual riding out on the wing of the B-52. The X-15 pilot obviously was a part of the B-52 team. He chatted and joked with them on the intercom unbeknownst to people on the ground or in the chase aircraft, but he could not get to them nor could they get to him in case of a problem. The early rocket aircraft were carried in the bomb bay of the mothership and thus, the crew of the mothership could help the rocket aircraft pilot in case of a problem. Being out on the wing, however, precluded any physical help, but the pilot could get a lot of moral support.
The ride out to the launch point was actually a pleasant ride, in some respects. The X-15 pilot could do a little sightseeing and he could critique the flying performance of the B-52 crew and make sarcastic remarks about their piloting abilities over the private intercom. They, in turn, might threaten to dump him out in the boondocks. From takeoff until 12 minutes to launch, the pilot was just doing housekeeping chores in the X-15. The checklist had very few items for the X-15 pilot to perform during this time. The B-52 crew was busy navigating out to the launch point with the assistance of ground vectoring. They were also topping off the X-15 LOX tank and aligning the inertial platform.
At 12 minutes to launch, I began activating the X-15 by initially starting the APUs. The APUs provided the essential hydraulic and electrical power to operate many of the other systems. We started them 12 minutes prior to launch to allow us to begin checking out the various other systems in the airplane to make sure they were all working properly before launch.
The radio communications illustrate the various checks performed before launch. The primary communications are between “NASA-1,” which is the pilot controller in the ground control room, the “B-52,” which is the B-52 pilot, “Butchart,” who is Stan Butchart, a NASA pilot who flew as a launch panel operator on the B-52, and “Chase,” which can be one of three different chase pilots depending on the phase of the flight. The specific chase is not always identified since it is difficult to know which chase pilot is speaking unless he calls out his number. Starting at 12 minutes to launch, the radio communications were as follows:
Thompson: “APU cooling switch going to normal.”
NASA-1: “OK, Milt.”
Thompson: “Pressure cooling coming on. My inertial altitude is just below 44,000, Butch and I’m reading about 1,000 foot per second on velocity.”
Butchart: “OK-want to reset your altitude? I’ve got just a hair shy of 1,000 foot per second velocity and oh, maybe about a couple of hundred feet down.”
B-52: “Eleven minutes.”
Thompson: “Attitudes look good and cabin source is 3,400 and you want the precool switch off now, is that right?”
NASA-1: “Right.”
Thompson: “Helium shutoff valve coming open. Hydraulic temperatures are OK. Data coming on, APUs coming on, number two.”
NASA-1: “Zero-zero-eight, (the call sign number of the B-52 bomber) let’s turn right 2 degrees.”
B-52: “Right, three-one.”
Thompson: “Number two APU is on. Pressure is 35 on hydraulics and holding. Starting number one.”
B-52: “Ten minutes.”
Chase-1: “Number one APU looks OK.”
Thompson: “I can’t get number one generator on—OK there she is. Engine reset. Hydraulic pressures are about 34 on number two APU and 3,500 on number one APU.”
NASA-1: “Roger, Milt.”
B-52: “Just past 9 minutes. Does 8 minutes still look good for the turn?” [The turn at 8 minutes is the turn back toward Edwards in preparation for the launch.]:
NASA-1: “Roger, Fitz.” [Fitz Fulton is the B-52 pilot].:
Thompson: “I’m on the controls and checking flap circuit breakers. Got engine reset. Data coming off.”
B-52: “Reading three-one degrees on heading.”
NASA-1: “Milt give us number two APU tank pressure.”
Thompson: “APU tank pressure is about 550 for both number one and number two. Mixing chambers temperatures are -35 and -45. Alpha [angle of attack] is about 1 degree and Beta [angle of sideslip] is about .5 degree to the left.”
Chase: “Will you try controls again, Milt?”
Thompson: “OK, here’s roll—pitch—and the rudder.”
Chase: “OK. And the flaps?”
Thompson: “OK, flaps coming down.”
Chase: “Flaps coming down.”
Thompson: “And back up.”
Chase: “Flaps up.”
Thompson: “OK, aux cabin pressure switch is on. Inertial platform is going internal—is that OK, Butch?”
Butchart: “Rog.”
Thompson: “OK, everything looks good. Fire extinguisher going to auto. Alternate SAS coming on.”
B-52: “Seven minutes.”
NASA-1: “That’s OK, Fitz.”
Thompson: “Starting SAS check—all channels are on—going to monitor. OK, they all came off and alternate SAS shows off. SAS check complete.”
NASA-1: “Roger.”
B-52: “Six minutes.”
Thompson: “Horizontal stabilizer at 0. Going to X-15 oxygen and oxygen pressure is 2,800. Cabin altitude is 35.”
NASA-1: “Your launch lake winds are southwest at 15.”
Thompson: “Roger, Jack.” [Jack McKay is the pilot controller in the control room.]:
B-52: “Five minutes to launch.”
Thompson: “OK. Data coming on. Data calibrate.”
NASA-1: “And Fitz—we will call the 4-minute point.”
B-52: “Roger.”
Thompson: “Tank handle going to pressurize. Ammonia tank pressure is 45 and LOX tank pressure is about 48.”
NASA-1: “Roger.”
B-52: “Two-one-four degrees.”
NASA-1: “Milt, check your ASAS switch on arm.”
Thompson: “ASAS is armed and I’ve got two jettison switches on jettison. Going to jettison now.”
NASA 1: “OK, Fitz. Four minutes now.”
B-52: “Four minutes, Rog.”
Thompson: “OK, Jack, intercom switch going off.”
NASA-1.: “OK, Milt. And data off?”
Thompson: “OK. How do you read now, Jack?”
NASA-1: “Five square and check your data off, Milt.”
Thompson: “OK. OK, Butch, I’ve got slightly under 1,000 on velocity and about 45,000-feet altitude.”
Butchart: “Altitude looks good in here, Milt.”
NASA-1: “OK, turn left two-one-two degrees.”
Thompson: “About 80 on number two and 100 on number one.”
NASA-1: “Fitz, turn left two-one-two degrees.”
B-52: “Two-one-two degrees. Three minutes now.”
NASA-1: “Roger.”
Butchart: “My inertial speed has dropped back to about 700, Milt.”
Thompson: “Mine’s just shy of 1,000.”
NASA-1: “Milt, did you get that 3-minute point?”
Thompson: “Affirm, Jack. I think I called everything off the checklist.”
NASA-1: “Let’s turn right 2 degrees.”
B-52: “Right 2 degrees, heading two-one-five degrees, coming back 3 degrees at 1 minute to go.”
Thompson: “Did you call 2 minutes yet?”
B-52: “Two minutes, now.”
; Thompson: “OK, data is on. Tape to 15. Push to test ball nose. Looks good. Alpha is still about 1 degree, Beta is about .5 degree left. Cine camera going to pulse.”
NASA-1: “Calibrate, Milt?”
Thompson: “Affirm, I got a calibrate.”
B-52: “One minute to go, picking up heading two- one-two degrees.”
Thompson: “OK, no head bumper. OK, we’ll call that 40 seconds. Prime switch to prime. Igniter- ready light. Precool switch to precool. And igniter idle. Coming up on 10 seconds, pump idle.”
NASA-1: “Everything looks good here.”
Thompson: “Manifolds and lines look good. Launch light going on. And we’ll call that three, two, one, launch.” (The bull and I were off on our journey.):
At this point I really got a shock. That launch was like being shot downward out of a cannon. It was a real jolt. No one warned me about the severity of the launch. This was due to the fact that the early participants in the program had flown so many flights that they had almost forgotten the early lessons learned. They, too, had been surprised by the hard launch, but they forgot to mention it to us new boys on the block.
The hard launch was primarily a result of the X-15 being trimmed for 0 g at launch to ensure a good clean separation from the B-52. Thus at launch, the X-15 went immediately from a stabilized 1 g flight condition to a 0 g flight condition and it remained at 0 g until the pilot initiated the pullup to round out and begin the climb. During the launch process, the X-15 would also roll off to the right unless the pilot applied some left roll input. This was due to the effect of the local flow field around the X-15 while on the pylon. Usually, it rolled off some even if he did apply some corrective roll control, because he never applied exactly the right amount.
In any event, I ended up in a 0 g trajectory with about 10 degrees of right roll. I decided the first thing to do was to try to light that engine to see if it was going to run. It lit off successfully and then I received my second surprise. The thrust of the engine forced my body back hard into the seat and headrest and effectively pinned me in that position for the duration of the powered portion of the flight. This was not a major problem, but it was a real surprise and it somewhat compounded my control task. In all my simulation practice for the flight, I had been very relaxed, smoking cigarettes, drinking coffee, and sitting in a slumped, head forward position. Now all of a sudden I was viewing the instrument panel from a completely different perspective and suffering from tunnel vision.
My instrument scan pattern that I had developed in the simulator was useless. I had to devise a new scan pattern in real time. To compound the problem, the pressure suit helmet had very little clearance in the small canopy, so when I attempted to move my head, I usually got hung up on a pad or the canopy structure. I had not used a pressure suit in any of my simulations prior to the flight, so I was surprised by a few of the minor problems associated with the suit. Again, the early pilots had practiced with the pressure suit in a simulation, but they had forgotten to recommend it to Joe Engle and me. It was not a big deal but it was another straw.
After the engine lit, I adjusted the throttle to 50 percent thrust, rolled the wings level and initiated the pullup to begin the climb. The flight plan called for a pullup to 10 degrees angle of attack which would be maintained until reaching a climb angle of +20 degrees. This pullup to 20 degrees required 26 seconds to accomplish. I was a couple of seconds late getting to 20 degrees due to the surprises and my delayed response time in getting the airplane started up hill. I was also late getting to my pushover altitude of 65,000 feet, but everything else was going according to plan.
At 83 seconds after launch, I was scheduled to extend my speed brakes to decrease my rate of acceleration. At 83 seconds, I should have accelerated to 2,800 feet per second and reached an altitude of 72,000 feet. I was a little low on both speed and altitude, so I delayed a couple of seconds before I extended the speed brakes. At 90 seconds, I had achieved the planned 3,100 feet per second, but I was about 2,000 feet low on profile. I finally peaked out at 74,400 feet at 100 seconds.
After reaching 74,000 feet altitude, I was supposed to maintain altitude while accelerating to 4,000 feet per second or about Mach 4. I unintentionally let the nose drop slightly and, as a result, I quickly built up a large rate of descent. At these high speeds a small error in nose position can produce a big altitude deviation. NASA-1 alerted me to the loss of altitude and I finally got the nose back up where it belonged. At 122 seconds after launch, I shut the engine down. I was traveling at 4,100 feet per second and I was at 73,000 feet altitude. In just over 2 minutes, I had gained about 30,000 feet of altitude and 3,200 feet per second of velocity or over three Mach numbers. This had been accomplished at half throttle and with the speed brakes extended for the last 30 seconds. That’s pretty impressive. A fighter pilot would give his left nut for an airplane like that.
After shutdown, I retracted the speed brakes and began a constant altitude glide toward Edwards. Energy management on this flight was pretty straight-forward since the flight was planned to be rather benign. There were no requirements for aggressive maneuvering to dissipate energy. NASA-1 vectored me to high key and guided me along the desired altitude profile.
NASA-1: “Ease it on over. Watch your nose position, Milt. We have you low on altitude. Bring it back up. Pull your nose on up, Milt.”
Thompson: “OK, it’s coming up.”
NASA-1: “Turn left 3 degrees. Bring it left 3 degrees.”
Thompson: “Roger, Jack.”
NASA-1: “Make it 5, 5 degrees. Speed brakes in. Turn left 3 degrees, Milt.”
Thompson: “Rog, Jack.”
NASA-1: “And maintain your altitude, you’re a little low, Milt.”
Thompson: “Rog.”
NASA-1: “OK, you’re about 10 miles from your checkpoint. Hold your altitude. And you’re looking very good here, Milt. Milt, delay your descent until you get over Cuddeback—we’ll give you a call.”
Thompson: “Rog, Jack.”
NASA-1: “And better go to land position on your test.”
Thompson: “Rog.”
NASA-1: “What is your velocity, Milt?”
Thompson: “I’ve got about two-point-four, Jack.”
NASA-1: “OK, you can start your descent now, you’re on profile. And we have you just northwest of Cuddeback. Do you have the field in sight?”
Thompson: “Affirm, Jack.”
NASA-1: “OK, we have you about Mach 2 here, Milt, and coming down through 70,000. Engine master off.”
Thompson: “Rog, engine master off.”
NASA-1: “And understand you have the field in sight, is that correct?”
Thompson: “Affirm.”
NASA-1: “OK, maintain what you have there, Milt. You have a good rate of descent here. OK, you can cut it to the left just a little, Milt.”
Thompson: “Rog, Jack.”
NASA-1: “180 would be a nice heading and keep your speed brakes in right now.”
Thompson: “Rog.”
Chase-4: “What’s your altitude, Milt?”
Thompson: “I’m coming through about 48 now.”
Chase-4: “Start your jettison, Milt.”
Thompson: “OK, going to jettison.”
NASA-1: “OK, you’re about 6 miles out of high key here, Milt.”
Thompson: “Rog, Jack.”
NASA-1: “One-point-two on velocity and watch your angle of attack.”
Thompson: “Rog.”
Chase-4: “I have a tallyho, got him in sight, he’s quite a little ways away. Kind of high, Milt.”
Thompson: “Rog. OK, am I about over the highway?” [The highway just north of the lakebed.]:
Now came the moment of truth. The deadstick landing. I had made it back to Edwards in reasonably good shape but now I was going to have to make an honest-to-God deadstick landing. I had only one chance. If I screwed up, I lost the airplane and maybe more. I had good energy for my approach. I was approaching the high-key position
with about 35,000 feet of altitude, which was the desired altitude. I had trouble determining my position over the ground due to the restricted downward vision in the X-15. As soon as I rolled into the turn to low key, I had a reasonably good view of the lakebed and the rocket site and I could judge my approach quite well.
I began to think I might really pull this off successfully. At the low-key position, I had about 20,000 feet—a little high, but I could always use some speed brake to kill off any excess altitude. The turn from low key onto final worked out well and, as I rolled out on final, I was just about right on the desired speed. I picked up my aim point on the edge of the lakebed and then I maintained speed and flight path angle until time for the landing flare.
Judging the landing flare was the final major task. A pilot did not have a lot of leeway for error, but by this time I felt pretty comfortable. As I passed through 1,000 feet above the ground, I started the flare to come level. I came level about 100 feet above the runway, lowered the flaps, and then dropped the gear. The airplane was flying very nicely now. I eased it on down to within 5 feet of the runway and just let it settle in.
The initial touchdown was very smooth, until the nose came down. The nose came down with a vengeance. For a moment, I thought the nose gear had failed as the nose slammed down on the runway. I did not realize how close the cockpit was to the ground in the landing attitude. I thought my butt was going to scrape the lakebed. It was a real jolt when the nose slammed down, about 8 g in the cockpit. From that point on, the pilot was just along for the ride. The airplane kind of slid out on its own. The last few seconds of radio conversation just prior to landing kind of sums up the flight:
At the Edge of Space Page 22