Behind the glamour boys in X-planes is an entire profession making sure your Cessna has its wings on straight.
- By D.C. Agle
- Air & Space magazine, January 2001
(Page 4 of 4)
What it does take to be an experimental test pilot is apparently not so much flying ability as assessment ability. Sure, you have to keep on target with climbs, dives, stalls, and even level flight within certain parameters, but ask any of these guys and he will tell you that most pilots can eventually learn to do that within acceptable levels. What sets them apart is their investigative nature, background in engineering, knowledge of what it takes to get FAA certification, and tolerance for paperwork and more paperwork. “There is an old saying in flight test,” Preston says: “An airplane doesn’t get off the ground until the paperwork at least equals its gross weight.”
While advances in the science of aviation have diluted some of the wild experimentation in experimental test flying, there are still problems that require a certain amount of seat-of-the-pants flying ability. Just this past year, test pilots at both Cessna and Piper were forced to declare in-flight emergencies and land their experimental prototypes on highways.
And experimental flights can have even more dire consequences. In 1980, Canadair’s new Challenger corporate jet prototype crashed, killing its chief test pilot, after an angle-of-attack indicator malfunctioned and the airplane stalled (another malfunction kept a temporarily deployed “spin chute” from separating from the aircraft after being engaged). In the course of testing its single-engine composite design over the years, relative newcomer Cirrus Design Corporation has experienced several crashes, resulting in the deaths of three test pilots, including former military test pilot and NASA astronaut Robert Overmyer in 1996.
While tragic to the experimental flight test community, hazard is expected from time to time. But experimental test pilots are also sometimes asked to revisit proven general aviation designs that have already passed the certification process and are flown on a daily basis by just plain folks with private or recreational ratings. And these programs can be just as hazardous as any initial flight test program.
“It was in April of 1966, the same week I was selected for the astronaut program,” recalls Apollo crew member Fred Haise, now a semi-retired aviation consultant. “This test almost ended my astronaut career before it got started.”
Haise was flying as a test pilot for NASA at Edwards Air Force Base in California when a call came in from the FAA. “They asked us to do a program on the Piper Twin Comanche which had a couple of accidents in which the tail came off in flight,” he says. For the former fighter pilot, flight test was flight test no matter if the airplane redlined at 190 knots or Mach 2. So he set about planning and flying a series of incrementally faster test flights trying to find out why the Twin Comanche’s tails were failing. “I would put it in a dive and when the airspeed stabilized at the number I wanted I would chop the yoke—hit it with my hand trying to induce an unstable series of oscillations that can mean real trouble for an airplane.” One day Haise chopped the yoke and the Comanche chopped back. “It was like riding a jackhammer,” he says. “I couldn’t read the instruments. I couldn’t get the controls to respond. But we got good data.”
The Comanche’s tail failed, but fortunately did not tear off the airplane, and the future lunar module pilot was able to land the crippled twin on Edwards’ dry lake. As a result of Haise’s experience, the FAA sent out an airworthiness directive that more than likely saved many lives. “I had a chase plane shooting the whole thing,” Haise adds. “The airplane looks like a bird flapping its wings. I understand the Air Force Test Pilot School still uses the footage as part of its curriculum.”
Test flights that become case studies for budding test pilots are rare. Usually pilots can spend their time doing what they do best: helping make good airplanes better—and having some fun in the process. Back aboard the multi-million-dollar Premier-I prototype, Bill Vavra and I are hauling the mail at 17,000 feet when Vavra suddenly turns to me and offers the controls. “Have some fun,” he says. “Really wring her out.” Soon we are skimming the cloud tops as I do my poor imitation of “really wringing her out.” But as no alarm bells are chiming, Vavra leans back in his seat and smiles. “You want to know what the best part of being a test pilot is?” he says. “This is it. We’re flying a high-performance jet, having a blast, and there is nobody in back so you don’t have to worry about them [dropping] their doughnuts.”