Spin Down
Thousands of Air Force pilots trained on the Holloman centrifuge. Now a better ride is coming.
- By Mark Betancourt
- AirSpaceMag.com, February 11, 2011
The Holloman centrifuge has been shut down after more than 20 years of training Air Force pilots.
USAF/ Senior Airman Veronica Stamps
(Page 2 of 2)
All technicians are required to undergo high-G centrifuge sessions themselves before they begin training students. That helps them understand the physiology of a high-G maneuver and better appreciate what the trainees are going through, which makes them better teachers, says Rivera. “If you’re going in there and you’ve never done it before, and you’re trying to talk to someone that’s struggling, it’s kind of hard to get through to them.”
In that spirit, techs-in-training deliberately G-LOC so they know what it feels like. They do this by cranking the centrifuge up to 9 Gs and simply breathing normally. Rivera says it takes about seven seconds to lose consciousness with that G-load. “Two normal breaths and you’re done.”
Regaining consciousness after a G-LOC is disorienting, similar to waking up from a nap. It can take a few seconds for trainees to figure out what’s happened and where they are. Rivera says one of his students woke up thinking she was in her bed back in San Antonio, worried that she was late for school.
Some students post video of their centrifuge training sessions on YouTube, which opens them up to jokes about their performance. But for fighter pilots, AGSM training can be a matter of life and death. In March 2009, an F-22 test pilot flying out of Edwards AFB was killed after he A-LOC’ed during a high-G maneuver. His fighter plummeted toward the ground as he tried to regain his focus, but it was too late.
“You gotta think that the AGSM is only a small piece in their pie when they’re trying to think about fighting maneuvers,” says Rivera. “We try to make this training so intense and so ingrained into their body and their muscle memory that it comes as second nature to them. Because if they’re doing all these other maneuvers… and they start pulling Gs, the possibility of them G-LOC’ing and people dying and losing aircraft just increases exponentially.”
Most of the centrifuge training crew from Holloman will move to Wright-Patterson, along with the researchers from Brooks. Rivera, though, will be staying on at Holloman to help with safety protocols. Among other things, he’ll be checking in on the pilots to make sure their AGSM stays sharp.
Rivera says he and his colleagues are excited about the future of centrifuge training. For one thing, the facility at Wright-Patterson will feature a few technical improvements over the ones at Holloman and Brooks. The new centrifuge will be able to swing its gondola in any direction, allowing trainees to simulate Gs in a number of thrust vectors. While some researchers study how the body is affected by different types of G forces, others will be able to test equipment like compressive G-suits that help pilots keep blood in their upper bodies.
Overall, Rivera thinks the combination of research and training will be a plus for both. “[Centrifuge work] has been slowly developing, it’s been improving,” he says. “We’re trying to make this program the best program out there.”
Comments (3)
The RAF doesn't fly F-22s so it couldn't have been an RAF F-22 pilot taking the last ride.
Posted by Alex on February 15,2011 | 11:22 PM
Youtube interview with RAF pilot in F22 exchange program.
http://www.youtube.com/watch?v=9aXYS0cmkQ0
Posted by Mark Breeding on February 19,2011 | 11:45 PM
Nice tribute to a very effective training program and to our dedicated, talented NCOs. Here is some history: The F-16 was the first fighter designed to pull and sustain 9G.
This extra 1.5G led to several GLOC fatalities - 1978 on. I was a family doc, and A-10 (a 7.33G jet) driver. So, I flew (slowly, since it was a Hog) to the USAF base in San Antonio. I became the first USAF "Pilot-Physician" in the F-16. The role of a PP is to analyze the intersect of physiology, psychology, and tactics to prevent accidents.
Sgt. Rivera is correct in that the training is designed to be ingrained, but he's optimistic. The AGSM is a demanding, counter-intuitive, psychomotor task: Hold all lower body muscles tense while breathing every 3s. Not easy, never automatic, and easily mis-performed. The AGSM requires attention in an arena that demands 110% cognition. Hence GLOC persists. In a recent F-22 loss the test point required 9G and a steep dive. A small distraction, an imperfect AGSM... and the sad loss of a talented test pilot.
The Holloman training was cost-effective because of the protective equipment: The WWII G suit worn then adds about another 1 -1.5G tolerance to your natural 5, or 6.5G. The muscle strain to elevate blood pressure to counteract the remaining 2.5G is tremendous. Trainee pilots ache for days afterwards and proudly show their "G measles" - broken skin capillaries from the unnatural venous pressure.
Todays fighter pilots benefit from a Full Coverage G suit and Positive Pressure Breathing for G, which enable relaxed tolerance up to about 8G. The remaining 1G can be sustained with a moderate strain, perhaps imperfectly performed - except in the "corner of the envelope".
The real solution to GLOC though, is to take the pilot out of the loop: If the jet will impact the ground, it recovers to level flight automatically. The technology is reliable and has been around for 15 years. The F-22 initially did not have such a program. It does now.
Posted by Geff McCarthy on February 24,2011 | 01:36 PM