Fighter Pilots Combat Jets’ Mind-Numbing Cockpits

While the nation’s military jet fighter pilots have been breaking the sound barrier and evading supersonic missiles, a deadly invader has crept into the cockpit.

It strikes when they are at the top of their performance, maybe in the middle of a dogfight, pulling turns that would make the roughest roller coaster seem like a carriage ride in the park.

Then they lose to GLOC (pronounced G-lock), gravity-induced loss of consciousness.

It begins as a pilot starts to feel the crushing weight from a sharp turn, or maybe a dive. In a modern fighter such as the F-16, maneuvers can lead to forces of 9 Gs, nine times the force of gravity.

Brain Becomes Drained

The blood becomes so heavy the heart can’t pump it; it drains from the brain. Things go gray; the pilot may suffer tunnel vision. Then black.

“It’s almost always fatal,” said Maj. Rocky Hill of the Air Force Inspection and Safety Center at Norton Air Force Base, Calif.

He said there have been at least 13 GLOC crashes since 1982, all but one fatal.

“We got so smart on it so fast and started running people through the centrifuge (for training), and we said this is a real success story. But it never really goes away,” Hill said during a seminar on prevention at Wright-Patterson Air Force Base, Ohio.

It becomes worse with a new generation of planes, the Air Force’s Advanced Tactical Fighter and the Navy’s Advanced Tactical Aircraft, planned for the next decade with more mind-numbing capabilities.

More Worries for Pilots

Pilots already are overloaded with computer screens, switches, gauges and dials, and GLOC is just one more worry.

“The cockpit is becoming an increasingly hostile area to the pilot,” Hill said.

Robert E. van Patten, leader of GLOC research at the Armstrong Aerospace Medical Research Laboratory at Wright Patterson, said Germans put meters in their Ju-88 dive bombers in World War II to pull the plane out at low altitudes if the pilot lost consciousness.

“All in all, we aren’t that far ahead,” Van Patten said.

Hill said GLOC gained priority again about four years ago when video cameras were put in cockpits. They captured pilots coming close to GLOC.

Susceptible pilots usually have many hours of flying time, but relatively few hours in high performance aircraft. They tend to be middle-aged and have had little training on the centrifuge, Hill said.

Reserves, Guard Susceptible

“These profiles very accurately describe our Air Force Reserve and Air National Guard units that have converted to the F-16,” Hill said.

Fatigue also is a big factor, researchers say, which could pose problems for a pilot flying multiple missions in wartime.

Beginning in August, the Air Force plans to train about 2,500 pilots per year--fledglings and veterans--on a new centrifuge at Holloman Air Force Base, N.M.

Part of the training involves exercises that push the blood back up.

So does the G-suit, a corset-like garment inflated to keep blood from pooling in the legs. Soon to come is positive-pressure breathing that forces air into the lungs and forces a pilot to exhale.

But even if a pilot does recover from GLOC, it can take up to two minutes to regain his bearings. So scientists are looking at ways to tell the airplane’s computer that the pilot is unconscious and the plane must briefly fly itself to safety.

Nearing One Solution

McDonnell Aircraft Co. said it is near a system that keys on a pilot’s breathing and voice patterns, combined with a computer memory of recent sharp maneuvers in the plane, to tell when a pilot is at GLOC risk.

Van Patten’s group is trying more complicated sensors, possibly in helmets, that would measure head slump, eye blink, blood pressure, pulse in head arteries and even the grip on the stick. Those researchers want to use more extensive artificial intelligence, including neural network--computers based on the architecture of the brain--to make more accurate judgments.

A pilot might someday put a computer disc with his own characteristics on board to tell the computer how to program the system exactly for him, Van Patten said.

To revive a pilot, researchers are studying ways to pulsate the G-suit, administering small amounts of carbon dioxide, which dilates blood vessels and raises blood pressure.

‘Plain Old Smelling Salts’

“Perhaps even plain old smelling salts,” said van Patten. “They have a long and honorable history.”

But most of all, a recent study shows, pilots want a system that they won’t have to attach each time they get into a cockpit and that they can override if it starts to malfunction.

Van Patten estimates that a simple prototype system could be built for $500,000 and could be ready to fly by 1993 with another $3 million. But in the current budget climate, he said, money is hard to come by.