DAYTON, OHIO ? When Scott Sharp crossed the finish line at the Indianapolis 500 in May, he could hear the cheers of his pit crew through an earpiece he used to communicate with them during the race.

The earpiece also was helping the military. Embedded inside was a tiny device used to detect and quantify the forces that pummel drivers during crashes. Air Force scientists are collecting the data to develop safer helmets, harnesses and ejection seats for military pilots.

Sharp, who had several concussions during crashes in 1997, welcomes the device.

“You don’t even know it’s there,” he said. “And it provides very valuable feedback.”

The Indy Racing League requires drivers to wear the special earpieces embedded with accelerometers, which measure the speed of the head during an impact.

Researchers at Wright-

Patterson Air Force Base also use human subjects in their labs, but can’t duplicate the gravitational forces that drivers endure because it’s too dangerous.

Joseph Pellettiere, technical adviser for the biomechanics branch of the Air Force Research Laboratory, said not only are the drivers subject to forces greater than those in the lab, but they get hit from all angles.

Brian Grattan, mechanical technician and operator, straps Air Force Staff Sgt. Brendan Cavanaugh into the chair of the horizontal impulse accelerator inside the Air Force Research Laboratory at Wright-Patterson Air Force Base on Nov. 29 in Dayton, Ohio. When Scott Sharp crossed the finish line in May at the Indianapolis 500, he could hear the cheers of his pit crew through an earpiece he used to communicate with them during the race. The earpiece also was helping the military. Embedded inside was a tiny device used to detect and quantify the forces that pummel drivers during crashes. Air Force scientists are collecting the data to develop safer helmets, harnesses and ejection seats for military pilots.

“They’ll hit the wall. They’ll flip up on the side. Sometimes they’ll flip and roll over,” Pellettiere said.

One thing the researchers are trying to do is help develop an ejection seat and harness for the Joint Strike Fighter, the Pentagon’s next-generation, all-purpose fighter jet.

Pellettiere said pilots who eject from such a plane can be buffeted by a 700 mph blast of wind and then get jolted when their parachute opens. The battering can injure their heads, necks and upper bodies.

In the Wright-Patterson test lab, mannequins and human subjects are strapped to a sled called a horizontal impulse accelerator. With a launch that sounds like the popping of a giant cork, the sled hurtles down a track, reaching speeds up to 120 mph in an instant.

A constellation of high-intensity lights overhead illuminates the sled for high-speed video cameras, which record every detail the forces have on the test subjects.

But the researchers also need the race drivers, who stand to benefit from the earpieces they wear. The IRL began using the data-collection earpieces several seasons ago, and plans to use the information to better protect drivers.

“There’s always been this cloak of mystery as to head injuries and what causes head injuries,” said Henry Bock, medical director of the IRL and Indianapolis 500. “We thought this would give us an opportunity, since these guys crash anyway.”

Bock said data has been collected from about 300 crashes, although in a few cases the earpieces fell out or disconnected.

• Air Force Research Lab

“We’ve had several very, very high-intensity crashes where we thought this would give us great data and we didn’t get anything,” he said.

Bock said officials are still in the data collection phase. The next step is to apply the information to make helmets and the cars more protective.

Racing officials and military researchers have been amazed at how drivers endure such great gravitational forces without suffering serious head injuries.

“These guys can hit their heads at levels that we never anticipated they would survive or walk away without concussions even,” said Ted Knox, principal scientist of the lab’s biomechanics branch.

Pellettiere said military scientists are looking at adopting a form of the rigid, carbon-fiber yoke used by race drivers that rests on their shoulders and supports their necks. A new earpiece is being developed with sensors that will measure six degrees of motion instead of only five. Pellettiere said it will include frontal rotation, one of the most important for military pilots.

“The issue is a pilot in a cockpit does a lot more looking around and needs a lot more head mobility,” he said.