Coming in loud and low, the flight of six F-16s roared across the Hill Air Force Base flight line, a tight formation that shed a fighter to the right and one to the left, the remaining four soaring straight up into the sky, trailing white smoke: The Thunderbirds had arrived.

The Thunderbirds are the premiere aerial demonstration and public relations team of the U.S. Air Force and the highlight of an open house and air show at the base Saturday.The open house runs from 9 a.m. to 5 p.m., including aerial demonstrations, flybys of current and vintage military and civilian aircraft, military bands, drill teams and numerous aircraft arrayed for inspection by curious visitors.

The event is free, the public is invited, and cameras are welcome for both ground exhibits and the air show.

There will be a brief ground ceremony at 2 p.m., then the Thunderbirds will fire up their blue and white F-16s 20 minutes later and take to the air at 2:30 p.m. for a 40-minute show.

Flying in the right-wing position in the

ormation will be Maj. Joe Bulmer, who is nearing the end of his two-year shift with the Air Force's elite flying team. Although looking forward to a new assignment, Bulmer said he'll miss flying with the Thunderbirds.

"Flying is too much fun to get tired of it, even with our schedule," Bulmer said, referring to the training, briefings, performing and public relations that makes up a typical 14-hour day for the crews.

"I've been to lots of places, met a lot of people and seen a lot of things in the last two years I wouldn't have otherwise," the major said. "But two years is just about the right time. I'm starting to look forward to a new assignment."

One of the highlights of Bulmer's stint with the Thunderbirds came last year when they visited the Far East, including China. It was the first aerial demonstration team to ever visit that nation, and, in fact, the first Free World fighters inside the country since the 1950s.

Bulmer is a New York state native and a 1977 graduate of the U.S. Air Force Academy. As a bachelor, the 230 or 240 days a year he's on the road - or in the air, to be exact - is a little easier on him than the family men in the unit.

Besides doing the air shows, the Thunderbird pilots visit schools, hospitals and attend a lot of receptions, all part of their work as representatives of the Air Force. "We do a lot of public relations work, but that's our function," Bulmer said.

As for the shows, months of training and hours of fine tuning go into making the aerobatics smooth and tight.

The formation maneuvers are designed to show the precision flying aspects of the F-16, along with their piloting skills, Bulmer said, while the solo aerobatics demonstrate the aircraft's capabilities.

Although in radio contact during the air show, the pilots are so finely tuned into their work they need little in the way of verbal commands, he said. Much of what they do is visual, keying off the craft ahead or beside them.

But safety in the air is not their only concern, Bulmer said, addressing a question that has cropped up frequently after the Ramstein, Germany, air show accident last month that wiped out a flight of four Italian fighters and killed more than 50 spectators on the ground.

After that incident, the Thunderbirds put their own routines under intense scrutiny, Bulmer said, but found nothing unsafe and nothing in need of changing.

The group flies under strict FAA regulations governing altitude and aircraft and crowd locations, Bulmer said. The crowd is kept at least 1,500 feet away from the runway where the aerobatics are performed and the single crossing maneuver is done at least a half-mile from the crowd.

"It's a very safe, conservative air show," the major said.