What scientists haven't solved and hot-shot pilots won't talk about.
- By William Gregory
- Air & Space magazine, May 2002
(Page 3 of 4)
Neal Finkelstein, an Army computer engineer, is dealing with the “tough guy” problem among infantry who use virtual reality helmets for battlefield simulations. Even though they have their feet planted firmly on the ground both in the chair and on the screen, “one in five is the drop-out rate,” he says, “and we’re still trying to figure out why so many people are getting sick. These big Army guys get in there and say ‘I’m really tough.’ But the more they fight it… They’ve got to back away.
“Helmets are tougher than screens. No other reference point is visible in a helmet, just that claustrophobic type of environment. Moving the head is not something people think about; they just automatically move it.”
Kelly Kingdon, a Canadian studying cyber-motion under Kay Stanney, shows off the test rig, one that comes closer to Kennedy’s wallpaper drum than what pilots meet in a simulator. A computer program generates a maze of three long corridors and 29 rooms onto a display in a Virtual Research B6 helmet, which has micro-optics that produce realistic immersion in a scene flowing by, comparable in quality to graphics on a home computer.
A single trip through the maze, self-driven with a standard computer mouse, takes 15 minutes and includes a set of mouse-actuated tasks. As you move through the corridors, various “jobs” pop up: Find the door to the hall in a room with psychedelic-colored walls; put three shapes—a star, a cylinder, and a circle—into slots. Throughout the test you have to keep “moving” down the hallways as synthetic scenery slowly flows by. If you move too slowly the scene goes into a roll. Though not as overpowering as being in Kennedy’s drum, the experience can be unsettling if the test goes on long enough.
Stanney’s students have put over 1,000 student volunteers through the test. Unlike pilots who go through screening, 90 to 95 percent of the students reported at least one symptom, like a headache, but only 1.5 percent got violently sick. Rupert says that in rare cases such symptoms can last for a month or two.
All of these tests have provided some basic answers, with more subtle solutions perhaps to come. Improving the technology for the virtual reality helmets will help. So will getting tough guys to back off and, just as important, hard-driving instructors to lay off.
When an instructor flash-freezes the simulator at 500 knots (575 mph) to start a new dogfight and cram in more combat per hop, he makes the student feel as though he’s smacked into a mountain. When a pilot’s cold grounds him, the first thing the operations officer does is send him to catch up on his simulator syllabus. Feeling below par, maybe with ear complications, the pilot is all set up for simulator sickness. None of these problems might be life-threatening, but what if the same pilot winds up in a regular cockpit the next day still feeling sub-par and slightly disoriented, because of subtle discrepancies between the simulator and his cockpit?
Researchers like Kennedy are trying to come up with basic guidelines to prevent such problems, including making sure pilots take shorter runs in the simulators. Both the Air Force and the Navy have tried adaptation drills. The Naval Aviation Aeromedical Research Laboratory in Pensacola, Florida, has a 20-foot rotating room called the Coriolis Acceleration Platform, in which people have lived as long as six weeks. The room constantly changes the rules of orientation. “It rotates very slowly,” Rupert says, “three revolutions per minute, one every 20 seconds.
“It’s like flying a single-engine piston aircraft,” he continues. “When you push the nose over, it tends to yaw to the left, because that blade in front of you is rotating clockwise. The same thing happens in the inner ear, in those little canals, in the rotating room.”
Because of its career-limiting implications, active-duty pilots hate talking about simulator sickness, but the longer they try to tough it out in a simulator run gone bad, the more severe their symptoms will get. Maybe they can console themselves with the knowledge that when it comes to enduring the virtual reality chair or helmet, sometimes it’s the most adept pilots who have the hardest time.