The Disorient Express
Despite the best training and technology, why do pilots still die from not knowing which end is up?
- By Tom LeCompte
- Air & Space magazine, September 2008
DEPT OF DEFENSE
(Page 3 of 7)
In 1926, Army Air Corps Captain William Ocker, who had been experimenting with Sperry’s turn indicator, took a medical exam that included a spin in a Barany chair to test his vestibular system. Experiencing the same spinning illusion, he had the revelation, writes William Langewiesche in Inside the Sky (Pantheon, 1998), “that instinct is worse than useless in the clouds, that it can induce deadly spirals, and that as a result having gyroscopes is not enough, that pilots must learn against all contradictory sensations the difficult discipline of an absolute belief in their instruments.” Ocker, with the zeal of a fundamentalist minister, began preaching the necessity of developing procedures and instructional programs in instrument flight. He was unable, however, to convert his superiors. Twice the Army had Ocker hospitalized to test his sanity. (In 1932, a vindicated Ocker coauthored the first treatise on instrument flying, Blind Flying in Theory and Practice.)
In 1927, a group of scientists and pilots that included Sperry and Army Air Corps Lieutenant James Doolittle built an artificial horizon, a gyroscopic device that gives the pilot a graphic representation of the airplane’s attitude in relation to the horizon. Doolittle used it in 1929 to make the first flight and landing solely by reference to the aircraft’s instruments, proving the feasibility of instrument-only flight.
Making trustworthy instruments was one thing, but making pilots trust them was another. At first, pilots reported the instruments seemed to work only in clear weather, that in clouds the devices went haywire, indicating turns the pilot was certain the airplane was not making. The instruments worked just fine; the pilots had to be taught to resist the instinct to fly “by the seat of their pants”—that is, by sensation alone.
Today, primary flight training for all pilots requires instruction in flight based on instruments and recovery from unusual attitudes, in which the flight instructor has the student close his eyes while the aircraft goes through a disorienting series of turns, climbs, and descents, then has the student return the airplane to straight-and-level flight. Military aviators, in addition to being subjected to periodic proficiency reviews, are required to attend, every five years, refresher courses in human physiology that include a section on spatial disorientation.
Rogers Shaw, a director at the FAA Civil Aeromedical Institute in Oklahoma City, admits that training exercises such as unusual-attitude recovery are limited by the fact that the student knows and expects to have to make a correction to return the airplane to straight-and-level flight. Spatial disorientation is so insidious, and the sensations it creates so compelling, that unless you suspect you have a problem, you would never know there is one. Unlike other airborne emergencies—an engine quitting, loss of electrical power, smoke in the cockpit—there’s no principal event to indicate anything is wrong. If the pilot does realize something is not quite right, he may react too late, or in a way that aggravates the situation. Or, as in the case of Major Young, the pilot may not react at all.
The crash of John F. Kennedy Jr. on the night of July 16, 1999, off the island of Martha’s Vineyard, which killed him, his wife, and her sister, brought public attention to the consequences of spatial disorientation. The investigation of an air crash, says Richard Bunker of the Massachusetts Aeronautical Commission, who investigated the Kennedy crash for the state, is a process of elimination. You start with the airplane. After eliminating structural or mechanical problems, you look at external factors, such as weather.
Then the investigation turns to the pilot. You examine his or her training and experience, medical history, personal life, and possible extenuating factors. Eventually, Bunker says, the evidence and the circumstances point to “well, maybe we’re looking at spatial disorientation.”
Kennedy did not have an instrument rating. He was flying at night over water with visibility as low as three miles in haze, meaning there were few lights and no visual horizon for reference. About 10 miles from Martha’s Vineyard, he deviated from course and made a number of maneuvers suggesting he was lost or disoriented. The final radar track showed the airplane in a tightening right-hand turn—called a graveyard spiral—that reached a descent rate exceeding 4,700 feet per minute before the airplane hit the water.