Tumbling with the Stars
Today’s airshow performers do it gyroscopically.
- By Debbie Gary
- Air & Space magazine, July 2009
Courtesy Greg Poe Airshows
(Page 3 of 3)
Around the early 1990s, many aerobatic performers shifted from biplanes to monoplanes, and that migration set off another radical change. When aggressive flying led to cracks in wooden wings, the solution was to make wings of composites—carbon fiber layers over lightweight, honeycomb cores. “Once they switched to the composite material, assuming the wing is laid up properly, they were just almost indestructible wings,” Greg Poe says. “And so then, once you get to that point, then you become comfortable and it is now a matter of your imagination, how you can tweak a maneuver, how you present it to the crowd. Now the airplane is no longer the weak link.”
With airplanes they could trust, pilots flew as hard as they wanted, and creativity blossomed. Three-time national aerobatic champion Patty Wagstaff, who flies a Cirrus-sponsored Extra 300S, points out that the inspiration for some of the new maneuvers came from unusual sources. “The knife-edge spin was a really interesting maneuver that came from the [radio control] modelers,” she says, “and Henry Haigh started doing it in competitions.”
Some aerobatic pilots found ways to manipulate their airplanes to mimic the true tumble, to fly them all the way through the gyroscopically assisted maneuver so they are in control, rather than just along for the ride. In his routine, Michael Goulian, the 1995 national aerobatic champ, does nine tumbles that are like perfectly choreographed dance steps, timed to a music soundtrack. “When I do a tumble,” he says, “the attitude and the direction of exit is absolutely predetermined every single time. In other words, I am doing the same tumble, with the same entry and the same exit, every time. It is a matter of spending hours and hours of learning how to do them.
“In a tumble you are always evaluating the attitude with which the plane is tumbling. Has it translated 90 degrees? How much energy is in the tumble? Am I going to do three rotations or four? In a tumble, you are thinking it through. You are not along for the ride. I will actually modulate the throttle and the rudder and the ailerons to fix a tumble that has gone bad…or to make it better, to make it flip one more time.”
I’ve watched him at shows: He pitches his Extra 300SHP forward at the top of a loop, yaws it sideways, and shows us the airplane tumbling from left to right while its nose peeks sideways at us. Then when it looks as if the airplane will rotate one more time, he stops mid-tumble, just because
Sean Tucker also taught himself to control the aircraft from the start of the tumble to the finish. “What I really focused on was how to fly the machine so I could do 9, 10, 11, 12 of them in a row across the sky,” he says. “It is not that difficult to do one of them, but to sustain one more than four or five times really takes finesse. It takes touch.”
Although they look wild, tumbles are not necessarily violent. “They have grown more aggressive and the perception is that they are out of control,” Tucker says. “Planes aren’t falling out of the sky and wings aren’t breaking off anymore, so they can’t be more violent. They are more dynamic, and that leads to the perception that they are more extreme. A nose-over-tail tumble is a zero-G maneuver. It is not violent. A centrifuge at high speeds will hurt you, though. It is 7 to 8 negative Gs. And a Bill Stein knife-edge spin is a lot of Gs.”
The best tumbling pilots practice relentlessly. “If you don’t practice them hundreds and hundreds of times,” Tucker says, “they will kill you at airshow altitudes. It all depends on what your altitude is. You always have to have your margins.”
It is not just the tumble a pilot has to prepare for, but also the spin that naturally follows a tumble. Japanese airshow pilot Rock Iwasaki was killed during a practice in 2005 while spinning out of a low-altitude tumble.
Tucker says, “I know that at 1,000 feet I can get out of an inverted flat spin, pull down and miss the ground, and still have energy. So any gyroscopic maneuver that I do, that I know has the potential to go into an inverted flat spin, always tops out at 1,000 feet above the ground, never at 800, even though you can do it all the time.”
At any altitude, performers flying tumbles thrill airshow crowds. Whenever I watch their routines, I remember a sticker Patty Wagstaff once had on the back of her Extra. “We’re professionals,” it said. “Don’t try this at home.”