Service Before Self
U.S. Air Force test pilots push themselves and their airplanes beyond their normal limits in order to ensure our safety.
- By Marc Barrera
- Apr 01, 2010
At approximately 10 a.m. on March 25, 2009, an F-22 crashed northeast of Edwards Air Force Base, killing David Cooley, 49, of Palmdale, Calif., a 21-year veteran test pilot. During the days of World Wars I and II, this may have been all too common an occurrence with test pilot deaths occurring weekly, but today, with advances in safety and technology, a test pilot's death happens on the average of once every two to three years.
Best of the Best
To become a test pilot for the U.S. Air Force, pilots must be accepted from a pool of applicants and go through an intensive 48- week course at the Test Pilot School at Edwards Air Force Base. Competition is fierce as most of the candidates are qualified for admittance many times over. All are minimally required to have an undergraduate degree, ideally in the fields of engineering, physical science, or mathematics. In addition, many have advanced degrees.
The requirements are high because so, too, are the stakes involved. As airplanes have become more complex, the necessary costs to manufacture them and the education required to fly them have increased exponentially. "We also are very careful in looking at their academic background," said Lt. Col. Bill Gray, 47, a/k/a "Evil Bill," chief test pilot at U.S. Air Force Test Pilot School. "We've discovered that it's very important to have people that are very smart and think like engineers or scientists during the flight test because you can give better feedback to the engineers as to what's going on and can then plan the tests better."
During the test pilot course, Gray said, students typically work 50- to 70-hour weeks, fly 70 to 100 sorties, and take 22 academic courses in their study of performance, flying qualities, systems, and test management. The curriculum has become so extensive that as of May 2008, the school has been accredited as a Masters Degree granting institute for Flight Test Engineering.
Test Hazard Analysis
The process begins with writing a test plan and a safety plan. According to Gregory V. Lewis, deputy director of the National Test Pilot School in Mojave, Calif., and president of the Society of Experimental Test Pilots, these plans can be hundreds of pages long, are written in strict detail, and are analyzed by a team of experts. "Prior to doing the test we analyze what unique test hazards could occur, identify the potential causes, and then develop special mitigating procedures to reduce the risk, or alternatively, reduce the negative consequences if the hazard occurs," he said.
For example, when conducting structural testing, one hazard is structural failure. Gray said there a lot of ways to mitigate this hazard. "First of all, we're going to figure out where the expected weak points on the aircraft are and we're going to put little strain gauges at the weak points so we can measure the actual stress or strain that the airframe is under," he said. During the flight test phase, a "buildup" process is employed. "You're very familiar with the buildup process," Gray added. "The first time you ever rode a bicycle, you didn't just hop on the thing and go zip it down a steep hill. You always start slow." With sensors around the airplane, the test pilot will test to airplane at a slow speed and his team will evaluate the data. If the data meet the team's predictions, then flight speed is increased.
Another example that uses the buildup process in reverse is testing for wing stall, which occurs when the wing is no longer developing enough lift . "You keep an airplane in level flight and you slow down, and as you go slower and slower you reach a point where the wings just can't hold the airplane up anymore and then the airplane will stall. Typically, that's characterized by the nose falling and — depending on the type of airplane — it may roll or it may enter a spin. Well, you want to be prepared just in case something like that happens," said Gray, noting that one option to employ the use of a spin chute. "Which means that if the airplane departs controlled flight, the pilot pulls a handle and a big parachute comes out of the back of the airplane and gets the airplane pointed nose into the wind again, and then the pilot disconnects the parachute and flies out."
The test process has become so comprehensive that it can take as long as a decade for an airplane to even receive initial operational capability. However, this is not time wasted when you consider the risks involved. "Test safety is a team eff ort," Lewis said. "It's not just the pilot, but a lot of people are working together to imagine what might go wrong and developing mitigating procedures to counter potential disasters. The importance of the work done by test teams on future generations of both pilots and passengers cannot be overstated."
This article originally appeared in the April 2010 issue of Occupational Health & Safety.