Joe Engle flew everything from Super Sabres to the Space Shuttle, but it is as an X-15 pilot that he is perhaps best known.
The last human footprints on the moon were left by Apollo 17’s Gene Cernan and Jack Schmitt in December 1972. Had things worked out as originally planned, however, those last prints would have been made by Cernan and U.S. Air Force pilot Joe Engle. But while he never set foot on the moon, Engle reached space long before Apollo even made it off the drawing board.
Born in Kansas in 1932, Engle graduated from the University of Kansas at Lawrence in 1956 with a degree in aeronautical engineering. From the start he set his sights on the sky, joining Air Force ROTC and earning his wings in 1958. Engle’s timing was perfect, as it was one of the most dynamic periods in aviation history—the “Blowtorch Era,” when the skies were filled with the constant roar of jet engines.
Engle served with the 474th Fighter Day Squadron (later re-designated the 309th Tactical Fighter Squadron) at George Air Force Base in California. Tactical Air Command’s job was to protect SAC bombers on airborne alert. Flying the supersonic North American F-100 Super Sabre, the squadron deployed to Europe at the height of the Cold War. But there were other enticements for an eager pilot like Engle. He wanted to reach the peak of the pyramid: flight test. At Wright-Patterson and Edwards AFBs, the Air Force was testing the fastest and most advanced airplanes in the world. Knowing he needed 1,500 hours of stick time to qualify, Engle flew everything he could. Asked about his favorite airplane, Engle replied, “My favorite was whatever I was flying at the moment.”
After graduating from the Air Force Test Pilot and Aerospace Research Pilot schools, Engle found himself on the threshold of not only flight test, but of space. The United States was about to go head-to-head with the Soviet Union in the race to send a man into space. Engle applied to join NASA, but watched as other Air Force and Navy pilots were selected to be the first to climb into rockets. However, with his extensive piloting experience, he was chosen for the next best thing: the North American X-15 hypersonic rocket plane. One of only eight men selected to pilot the black X-15, Engle flew it 16 times, surpassing the 50-mile altitude boundary that the Air Force recognized as “space” three times, and earning his astronaut wings. Engle said he felt the X-15 was “the ultimate airplane I could possibly fly.”
The X-15 pilots, who included the soon-to-be-famous Neil Armstrong, pioneered and proved many of the techniques and hardware that would be invaluable to the future of space exploration. Even after Engle was selected to join the fifth astronaut group in 1966, he would find his experience in the X-15 played a major role during his time at NASA.
With the Gemini Program winding down, NASA had its sights squarely on the moon. Engle was ready, having been selected as the Lunar Module pilot for the Apollo 14 backup crew and the prime crew of Apollo 17, commanded by Cernan. During the triumphant days after the success of Apollo 11 and Neil Armstrong’s “one small step,” however, NASA found public support and congressional funding for the Apollo program waning.
Apollo 18, 19 and 20 were cancelled. The last manned moon landing would be on Apollo 17, with Engle slated to pilot the Lunar Module. But he would not get the chance. NASA, under pressure from the scientific community to have a qualified geologist on the last flight, replaced Engle with Harrison “Jack” Schmitt. “I was very disappointed,” Engle admitted, “but as any test pilot will say, you don’t always get the flight you want. I understood what had to be done.”
Yet it wasn’t the end of Engle’s dreams of flying in space. He conferred with Deke Slayton, head of the astronaut office, about his future in manned spaceflight. Slayton, a former Air Force test pilot himself, was considering astronauts for the Apollo Applications Program, genesis of the Skylab space station. But another program was then under development, a reusable space shuttle slated to begin flying in the early 1980s. “When I was talking to Deke,” Engle said, “the shuttle kept coming up in the conversation. Deke said my stick-and-rudder time in the X-15 was a valuable skill for the shuttle program.” In fact, one of Engle’s X-15 flights determined that a space shuttle would not need air-breathing engines, i.e., jets for control during re-entry from orbit. “We proved that a shuttle could be brought in from a speed of Mach 25 to a landing with thrusters and aerodynamic control alone,” he said.
Thus in late 1977 Engle found himself at the controls of the space shuttle Enterprise, commanding one of the two test crews. Carried by a modified Boeing 747 to an altitude over 20,000 feet and released, the shuttle glided to a landing at Edwards. As the shuttle Columbia made its maiden spaceflight in 1981, Engle was in training to command the second orbital mission, STS-2, with pilot Dick Truly. After testing the Shuttle Remote Manipulator System “CanadArm,” Engle and Truly flew Columbia from orbit to touchdown totally under manual control—the first and only time an aerospace vehicle was manually flown from Mach 25 to landing. This was the legacy of Engle’s pioneering X-15 flights almost 20 years earlier.
“Personally for me the highlight of the mission was to be able to look out of the windows at the Earth hanging overhead,” Engle said. “It was an awesome experience.” He also commanded the 1985 STS-51-I mission, during which Discovery’s crew launched three satellites and retrieved and repaired another. In the end, Engle had spent more than 200 hours in space. Now an adviser for the International Space Station, Engle continues to lend his expertise and experience to further NASA’s space exploration goals.
On his retirement from the Air Force in 1986 as a major general, Engle had amassed a remarkable career in the air, logging nearly 15,000 hours in more than 185 different aircraft types. While at the controls of the X-15, he participated in one of the most successful high-speed, high-altitude research programs in history. Today he is the last living X-15 pilot.
This feature originally appeared in the November 2017 issue of Aviation History. Subscribe today!