In the unglamorous underbelly of Philips Arena sits the Hawks practice court.

Usually, its purpose is for Jeff Teague, Josh Smith and the rest of the local NBA crew to practice their dribbles and dunks.

But once a week for two hours, the sound on the court isn’t only the thump of a basketball but also the squeak of a mini trampoline and the thud of a body landing on a foot-and-a-half thick crash mat.

It’s rehearsal time for SkyHawk and his teammates on the Sky Squad.

If you’ve attended an Atlanta Hawks game, you’ve witnessed the aerodynamic — emphasis on dynamic — acrobatic dunking prowess of the sleek, buff superhero SkyHawk and his tank-top-and-shorts-clad buddies.

Sometimes they command halftime with a five-minute, gasp-inducing performance as they demonstrate moves with names such as the “peanut butter and jelly” (a backward turn and twist on the trampoline before dunking) or a tandem jump that involves passing the ball to each other in midair after springing off the tilted trampoline.

Other times, if the game is tight and the crowd needs amping, SkyHawk and Sky Squad will drag their gear onto the court during a third- or fourth-quarter timeout for a handful of tricks.

This sport — and it is an official one, called “acrodunking” — is dangerous and not meant for gymnasts who cringe at blood or unnaturally bent limbs.

At a recent Tuesday night practice, SkyHawk — whose identity must remain anonymous because he is, after all, a superhero — knocks on a metal folding chair.

“By the grace of God, I have not had a serious accident. The worst thing? I hit my head on the [basketball] rim. But I have a hard head,” he said with a grin.

OK, so even superheroes take off their bird head and 10-piece Lycra costume sometimes.

What we can tell you about SkyHawk is that he lives in Ellenwood, teaches aerobics several days a week at the Harriett G. Darnell Senior Multi-Purpose Facility in Atlanta and runs a DJ company that specializes in weddings and corporate events.

He’s also childhood friends with Sky Squad member Phillip Davis; the two of them started their gymnastics career at Kidsgym USA in Fayetteville when both were 10. Now, they’re 28.

In fact, many of the guys on the current Sky Squad — Javoris Carlisle, Andrew Cyrus, George Jones, Chris Wheaton, Eric Locklin — are longtime friends who also trained with Houston-based Jerry Burrell, widely considered the godfather of acrodunking.

The group, which works for the Hawks as an independent contractor, has performed with the UniverSoul Circus, during the Harlem Globetrotters halftime show and at Legoland in California.

Their established bond is especially beneficial when bodies are 20 feet in the air with a backboard inches from their noses.

“That so many of the guys have known each other 10, 15 years, that’s a testament not only to their talent but their friendship. It’s a relationship like a quarterback and a wide receiver, that feeling of, ‘I know the guy behind me is going to have my back and get [the ball] in,” said Matt Payne, senior manager of Hawks Game Presentation. “These guys make it look so easy.”

But the job hazards are very real.

At the beginning of this season, Davis, a civil engineer who also teaches children’s gymnastics at the Carl E. Sanders Family YMCA at Buckhead, rolled his ankle during practice, an injury that still nags him.

But his scariest moment came when his left leg got caught on the rim during an in-game performance — and he somehow hopped away unscathed.

“It’s all about timing and coordination. You can never have too much practice,” said the lithe Davis.

“I am always nervous before I go out,” added SkyHawk, a buff, handsome fellow whose biceps are noticeable, if not superhero cartoonish. “I’ve performed in front of thousands of people — 18,000 if we’re sold out here — and I’ve been in bigger arenas, too. But it still doesn’t matter. When you’re hitting the trampoline and going at a basketball rim that doesn’t move, it’s nerve-wracking.”

SkyHawk has been part of the Hawks’ in-game experience since the mid-’90s, with various gymnasts sporting the Spandex —the current SkyHawk is in his third season. He co-exists peacefully with mascot Harry the Hawk; they both do whatever is necessary to ignite the crowd, whether it’s passing out candy to kids or hoisting an air gun to shoot T-shirts into the stands.

And both serve different purposes.

“Harry is the fun prankster and SkyHawk is the more serious superhero. He has his muscles and that powerful, swooping thing, whereas Harry will spray silly string and dance like Michael Jackson,” Payne said.

SkyHawk is present at every home game, but the Sky Squad usually only performs on weekends and when the Hawks play a marquee team or in a game with added significance. Davis said he knows of only a few other NBA teams that employ airborne gymnasts — among them the Washington Wizards, Milwaukee Bucks, Miami Heat and Orlando Magic.

But the rewards of participating in the breathtaking spectacle displayed by SkyHawk and Sky Squad seem to outweigh the occasional split lip or mid-air collision.

For Davis, it’s “being able to show what I feel is a God-given talent. I would go out there and do it for free for the rest of my life if I could. I love gymnastics. I love being able to tumble. I love feeling free when you’re in the air.”

SkyHawk said it’s worth having his peripheral vision challenged and sweating in his daredevil uniform “to see the facial expressions on the kids and the emotion they give off. They think, ‘Hey, a superhero is coming over to say hi to me.’ It makes their day.”

And for Payne, it’s making sure the crowd leaves with a lasting impression.

“I just tell [SkyHawk and Sky Squad], make sure that last ball goes through the hoops.”

Catch the action

Sky Squad performs during the Hawks games 7 p.m. March 3 and 7:30 p.m. March 19. $10-$165 March 3, $35-$321 March 19. Philps Arena, 1 Philips Drive, Atlanta. 1-800-745-3000. ticketmaster.com