First Man

by James R. Hansen

  Whatever caused its pitch-up, Yeager’s plane fell over on its back and went into a flat spin. Spiraling down and down from over twenty miles high, Yeager struggled to right himself. At 21,000 feet, he popped open the parachute rig stored in the tail of the NF-104A, a desperate move that failed to get him out of the spin. At 14,000 feet, he had no option but to eject. Blasted out of his plane, Yeager became entangled in his ejection seat and, awash in leftover rocket fuel, suffered horrible burns to his face and hands. As shown in the movie, he hit the ground hard and in excruciating pain. Nonetheless, Yeager resolutely got to his feet, loosely gathered up his chute, and, with flight helmet under his arm, walked almost staidly away from the burning wreckage toward an oncoming ambulance. That is, at least, the glorified Hollywood image. More accurately, a motorist from a nearby highway immediately rushed to assist Yeager, only to vomit at the sight of Yeager using the man’s penknife to cut off one of his lined gloves, as well as parts of two badly burned fingers stuck to the rubber lining.

  Unfortunately, so much else about Yeager and his December 1963 flight as romantically inflated in The Right Stuff and elsewhere is factually inaccurate.* Most important, Yeager and the U.S. Air Force Test Pilot School at Edwards were not responsible for “develop[ing] the first techniques for maneuvering in outer space,” as some air force publications and Web sites have claimed; NACA/NASA was, with the F-104 and previously with the X-1B. (The X-1B flights occurred between November 1957 and January 1958, but they were not effective in terms of reaction-control research.) And Yeager was not even close to being the first pilot to zoom into the high stratosphere. As we have seen, some NASA test pilots began to make zooms to 90,000 feet as early as the fall of 1960, a full three years prior to Yeager’s December 1963 flight. And in the rocket-assisted NF-104A, air force pilots performed zooms into the upper stratosphere before Yeager, as did Lockheed test pilot Jack Woolams.

  Also, well before December 1963, a far more remarkable and historically significant flying machine had pushed the envelope considerably further than any zooming F-104. This machine was the X-15, the fastest and highest-flying manned winged vehicle ever built—and one that Chuck Yeager never flew. Conceived by the NACA in the early 1950s and built by North American Aviation (later North American Rockwell) under the sponsorship of the air force, the navy, and the NACA, the X-15 was constructed not just to explore the hypersonic flight regime existing above Mach 5 but also to study the possibilities of flying a winged vehicle outside the sensible atmosphere (the region where aerodynamic control surfaces will function). First flown in June 1959, the rocket-powered X-15 was a veritable “aerospace plane.” By the end of 1961, the year President Kennedy committed the nation to the Moon landing, the X-15 attained its primary design goals of flying to a speed in excess of Mach 6 (over 4,000 mph) and to an altitude of over 200,000 feet (or nearly thirty-eight miles high). In 1962, a year that saw the Mercury flights of astronauts Glenn, Carpenter, and Schirra, air force pilot Robert White, in a pressure suit similar to the Mercury space suit, flew the X-15 more than fifty miles high (264,000 feet), the altitude that technically qualified him as an “astronaut” according to a policy invented by the U.S. Air Force (and never endorsed by NASA). The total number of X-15 pilots who earned “astronaut wings” according to the air force definition was eight. That was one more than the original group of Mercury astronauts, only six of whom made it into space (and only four into orbit) as part of the Mercury program.

  Following over thirty zooms in the F-104, Neil Armstrong would fly the X-15 seven times before joining the second class of American astronauts in September 1962. Neil never made it above the fifty-mile mark, but on April 20, 1962, in his sixth X-15 flight, he did reach 207,500 feet, just under forty miles high.

  In retrospect, the movement of aeronautics from subsonic to transonic, then to supersonic and on to hypersonic (and beyond that to “hypervelocity”) seems inevitable. As the emerging Cold War crystallized into an atomic face-off between the United States and the Soviet Union, the sharpest focus for hypersonic enthusiasm lay in the development of an intercontinental ballistic missile (ICBM) armed with nuclear warheads. Yet for those enthusiasts for whom aeronautics still meant piloted, winged airplanes, the ambition was to design a rocket-powered vehicle to take men and cargo on hyperfast flights across global distances, on trajectories that, at their apex, flew out into space.

  Rocket-powered experimental research airplanes were air-dropped into flight. Armstrong piloted his first on August 15, 1957, the first check-out flight of the modified X-1B, zooming to about 60,000 feet. Although it was the highest altitude that Armstrong had yet flown, at only 11.4 miles the dynamic pressure simply was not low enough to test the reaction controls.

  In landing the aircraft, his nose landing gear “failed.” According to Neil’s official report, he “inadvertently touched down at 170 KIAS [Knots Indicated Airspeed], nose wheel first.” “It didn’t really fail,” Neil admits, “I broke it. I was landing on the lake bed, and it was fairly normal. But at touchdown the airplane began to porpoise and, after several cycles of the porpoising, the nose wheel bracketry failed. I felt devastated, of course, but that was improved a little when I found out that was the thirteenth or fourteenth time [due to the coupling of the geometry] that had happened [with the X-1 series].”

  In his second flight in the X-1B on January 16, 1958,* Armstrong remembers, “we dropped too close to Edwards Dry Lake [due to some systems problems on the X-1B], so we aborted the zoom.” The X-1B flew only one more time, on January 23, 1958, when Armstrong and Stan Butchart air-dropped pilot Jack McKay for a zoom to 55,000 feet, one that did not slow enough at the top to check out reaction controls. Immediately after McKay’s flight, mechanics found irreparable cracks in the rocket motor’s liquid oxygen tank (by then, the X-1B was about a ten-year-old plane), ending the entire X-1B program.

  Supersonic jets differed from their slower predecessors in the design of their relatively shorter swept-back wings, denser shapes, and a much greater mass concentration around their fuselages. Unexpectedly, this altered geometry brought on some serious aerodynamic difficulties known as “roll coupling” (also called “inertial coupling” or “roll divergence”).

  As Armstrong reported to work at the HSFS in the summer of 1955, no problem was receiving more attention than roll coupling. Not only was the problem endangering the F-100, it had also threatened the D-558-2, X-2, and the NACA’s newest research airplane, the Douglas X-3. A long, slender, dart-shaped aircraft that rates as one of the fastest-looking aircraft ever designed, the X-3 Stiletto experienced coupling instability during abrupt roll maneuvers that caused it to go wildly out of control. Built for Mach 2, the X-3 was barely able to reach Mach 1.2 because it never received the higher-rated-thrust turbojets intended for it. The NACA retired the plane, which was underfunded and lacked expected engine performance, in May 1956 after only twenty flights. So all the attention turned to the F-100. Quickly, a fix was found—the addition of a much larger tail. Then, flying its own modified F-100C, the NACA tested a new automatic control technique—one that used pitch damping as a means of lessening the divergency yaw during high roll rates—to resolve the roll coupling problem more generally. Armstrong checked out in the airplane on October 7, 1955, and piloted many of the flights for that program during the next two years.

  This partially automatic flight-control system that Armstrong helped to develop for the F-100 was one of the first to incorporate “feedback compensation.” In essence, the idea was for the control surfaces on the aircraft (ailerons, rudder, elevator, and such) to communicate as part of an integrated, self-regulating system. What was needed for the X-15 was a novel system that automatically monitored and changed the “gains,” i.e., the ups and downs in voltage necessary to adjust the flight control system, without requiring too much work from the pilot.

  The stability augmentation system used on the first two X-15s did not live up to expectations. Armstrong explains: “Because the X-15 covered
such a wide speed range, it was impossible to set the gains in the flight control system to a single value that was optimum for all flight conditions. You had to continually be changing the gains because at one minute you’re at Mach 1, the next minute you’re at Mach 5.” This was “a complex and bothersome nuisance, a high workload environment.”

  Starting in April 1960, Neil consulted with engineers at the Minneapolis-Honeywell Corporation on “a very unique, self-adjusting system.” After Honeywell installed the prototype system—called MH-96—on an F-101 Voodoo in early 1961, Armstrong traveled to Minnesota in March 1961 to fly it. Based largely on Neil’s favorable written reports, NASA decided to install the MH-96 on the final X-15 (X-15-3), which was scheduled to be test flown for the first time late in 1961. Given his role in the MH-96’s development, NASA assigned Armstrong to pilot the first flight.

  In Minneapolis as at Edwards, Neil explains, “We used airplanes like the mathematician might use a computer, as a tool to find answers in aerodynamics.”

  The NACA’s High-Speed Flight Station virtually invented the flight simulator for research purposes. In 1952, the NACA convinced the air force to buy an analog computer known as GEDA (Goodyear Electronic Differential Analyzer). Set up on the military base and maintained by electronics technicians, the inspiration and talent for turning the machine into a real flight simulator fell to two young engineers from the NACA, Richard E. Day and Joseph Weil. They programmed the necessary equations of motions into GEDA, gave it a simple broom-handle control stick, and set it up to “fly” what amounted to the first “virtual” airplane with a variation on “degrees of freedom” (roll; move forward and backward; and go up, down, and sideways). Day and Weil chose to give their pioneering simulator one freedom less, massively simplifying the overall equations by holding the forward speed constant. Changes in any one of the five flight quantities fed back into the program’s equations, changing the quantities of the other four.

  By the time Armstrong arrived at Edwards, flight simulators had made important contributions to a number of research programs, notably the X-1B and the X-2, the latter of which the NACA was supposed to receive after the air force finished testing it. Unfortunately, a needless tragedy with the X-2 stopped that from happening.

  Dick Day warned his air force associates not to push ahead so fast with the X-2, piloted by Iven Kinchloe, Frank “Pete” Everest, and Milburn G. Apt. Data from their work with the GEDA was confirming evidence from NACA wind tunnel tests that the X-2 would experience “rapidly deteriorating directional and lateral (roll) stability near Mach 3.” On April 25, 1956, the X-2 broke the sound barrier for the first time. Less than a month later, it flew past Mach 2. By midsummer it was pushing Mach 3. When Mel Apt took the X-2 up on September 27, 1956, for his very first flight in the aircraft, his flight plan called for “the optimum maximum energy flight path,” one that, without question, would rocket him past Mach 3—and into roll coupling.

  The fatal crash happened just as Dick Day thought it might. At 65,000 feet and a speed of Mach 3.2, Apt lost control of the X-2 due to roll coupling and became unconscious. By the time he came to, it was too late. He died instantly when the plane screamed into the desert floor.

  On the ground that day in the company of air force test pilot Iven Kinchloe, Armstrong observed the disaster from start to finish: “Mel’s flight was to be the last air force flight of the X-2 prior to turning the aircraft over to the NACA. So there was a good deal of interest in each X-2 flight. NACA HSFS was wedded to the concept of step-by-step testing so we were appalled that the air force would be putting any pilot on such a difficult profile on his first flight. In the air force quest for yet another record, they were deviating substantially from the NACA approach. So we tended to blame the air force officials for the accident, the loss of Mel, and the loss of the one-of-a-kind aircraft.”

  The irony is that, in Mercury, Gemini, and Apollo, NASA did approximately the same thing as the air force did with the X-2. The difference was, in Armstrong’s view, that “our simulators in the space program were so much more sophisticated and accurate, and our preparation was so much more intense, that we convinced ourselves that the pilots could handle whatever situation we might encounter in flight.”

  The Apt tragedy deepened the NACA’s commitment to the development of its research simulators. From GEDA and Dick Day’s other very early simulators came the Sim Lab, which Armstrong inhabited with increasing frequency: “I was often in the Simulation Lab at the request of one of our flight test engineers or simulation engineers to check out something about some simulator mechanization. We were trying to increase our understanding of aircraft handling qualities, damping limits, and what was causing instability.”

  In the Sim Lab, Neil learned “that there were many ways to induce errors into the programming. Often the outputs to the instruments were improperly mechanized so the instrument would not accurately represent the airplane motions. I found this to be true much later in Houston and always took the time with a new simulator to check the accuracy of its response.”

  “In those days, pilots didn’t really trust simulators,” remembers flight simulation programmer Gene L. Waltman, who came to work at the HSFS in July 1957, shortly before the transition from the NACA to NASA, “especially the older pilots.” For most of them, “what went on in a simulator just didn’t look or feel right.” Dick Day remembers one older pilot who after being coaxed into the Sim Lab and making a single simulation, said to Day, “‘Well, that’s enough. Let’s go to the bar.’ And that’s the way his actual flights looked.” On the other hand, according to Day, “Neil believed in the simulations…. because he could see the results.” “Always picking up new things and researching new things,” Armstrong may have spent more time in simulators than any other pilot then at Edwards.

  Long before the Mercury astronauts “rode the wheel,” Armstrong also became one of the first NASA test pilots to endure the torture of the navy’s Johnsville centrifuge “to see whether the g field that you had to go through in a rocket-launch profile would adversely affect your ability to do the precision job of flying into orbit.” Armstrong explains the purpose of the research: “We hypothesized that it would be possible to pilot an aircraft into orbit—that a vertically launched rocket could be manually flown into orbit without the need for an autopilot or any sort of remote control.”

  A team of seven pilots took part in the experiment: Armstrong, Stan Butchart, and Forrest “Pete” Petersen from the FRC; two other NASA pilots, one from Langley and one from Ames; and two air force pilots. Lying on their backs and strapped into molded seats contoured to fit the form of the individual pilot in his pressure suit, Armstrong and his mates were put through the wringer. Every possible force and stress and every possible flight condition was brought to bear on the pilots as they whirled dizzily at the end of the fifty-foot-long arm. At the highest speed and angle of the wheel, they experienced acceleration rates as high as fifteen g’s. Only a couple of the pilots handled g forces that high, and Armstrong was one of them. Gene Waltman, one of the FRC technicians on the scene, remembers Armstrong saying that at fifteen g’s so much blood left his head that he could only really see one of the instruments in the simulated cockpit. “I’d watch them get sick!” recalls Roger Barnicki, another FRC technician specializing in pilots’ flight suits. “Neil was not one that got sick. Neil was one that did his fifteen and got out of there!”

  Neil recalls, “We persuaded ourselves at least—I don’t think we persuaded others—that it was, indeed, a doable task, operating the controls of a launch vehicle or aircraft accelerating at those high rates.” With FRC engineers Ed Holleman and Bill Andrews, Armstrong coauthored a NASA report announcing the surprising results. Many people in the aerospace community questioned the finding that g-forces up to about eight g’s actually had very little effect on a pilot’s ability to operate flight controls until it was proven to be true in the X-15 and Mercury programs.

  Armstrong later went back to
Johnsville to fly X-15 entry trajectories with various flight control system settings. “This was the most complicated centrifuge simulation ever created, as it attempted to provide a complete closed-loop simulation with the lateral and vertical components of the accelerations produced due to the pilot control actions reproduced in the centrifuge’s gondola cockpit.”

  But the key component of X-15 flight preparation was the electronic simulator. Two main X-15 simulators were built. Both of them were analog machines, because digital computers were still far too slow to do anything in “real time.” North American erected the simulator called the “XD” on company property on what is now the south side of Los Angeles International Airport. Armstrong visited several times to experience the simulation of all six degrees of freedom. Flying down in an R4D, Day remembers Neil regularly asking for an ILS (instruments) approach into Los Angeles airport. “We did several flights down, basically entries. We would go up to 2,500 or 3,000 feet and we would do entries at different angles of attack and then plot angle of attack versus maximum dynamic pressure. It turned out to be a straight line, which was a special equation. And Neil learned that in case he had trouble.”

  Under Dick Day’s direction, NASA built at Edwards an X-15 simulator that replicated the X-15 cockpit. According to Armstrong, the machine was “probably the best simulator that had ever been built up to that time, in terms of its accuracy and dependability.” In preparation for each one of his seven X-15 flights, he spent fifty to sixty hours in the simulator.

  “The actual X-15 flights were only ten minutes long, and generally in the simulator you didn’t have the ability to do the landing,” Neil explains. “You’d just do the in-flight, and they were only a couple minutes long. We would put together a little team—the pilot, one of the research engineers, and one of the guys from the computer group—and say, ‘Here’s what we want to do,’ and they’d take what data we had and put it in and find out what we could learn from it. You could kind of begin to understand a problem.”