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Rush to Judgment

Art by Lou BeachWITH EACH WELL-PUBLICIZED AIRPLANE ACCIDENT, another of the mysteries of the pilot's world is laid bare to the public. ValuJet unveiled solid-oxygen generators (the dirty little secret of the drop-down mask!). Swissair 111 uncovered fuel dumping and maximum landing weights. And now JFK Jr. has exposed the Instrument Rating.

The rating is an appendix to a pilot's license that authorizes him or her to fly without visual reference to the horizon or the ground. John F. Kennedy Jr. had been studying for one before his small plane, with his wife and her sister aboard, plunged into the waters off Martha's Vineyard. Everything about the accident pointed to a sudden loss of control: the unmotivated right turn indicated by the final radar echo, the lack of a distress call, the precipitous descent that could only be achieved, in a Piper Saratoga, by banking very steeply or by rolling the airplane over onto its back. One explanation is that Kennedy lost his visual bearings; so media pundits have decided the instrument rating that he did not have would have saved him.

But the accident scenario is not so simple and obvious. As a private pilot and instrument student, Kennedy already possessed the basic instrument-flying skills that he needed to find his way to Martha's Vineyard airport in hazy conditions, or, failing that, to turn back toward the brightly lighted Connecticut coast. Nor does his inexperience necessarily explain anything; Navy pilots with the same number of hours as Kennedy are landing jets on carriers. Despite some nonsensical pronouncements to the contrary, Kennedy's was not a "high performance" airplane (except perhaps in the view of Piper salesmen) and did not require a "butterfly touch" to fly. And it was equipped to fly itself.

THE INSTRUMENT RATING IS NOT THE PANACEA the pundits would have us believe. The experience requirements are very minimal: You must have a private pilot's license, with 40 hours of instrument practice, of which 20 may be logged in front of a home computer. There's a flight test, and a written exam that many pilots dread as one of the more daunting challenges in aviation.

The fundamental reason for the instrument rating is that you can't keep an airplane upright just by "seat of the pants" feel. The balancing apparatus in the inner ear is unable to distinguish between position and motion. That ambiguity accounts for the illusions you get in Disneyland's Star Tours ride, which is, in fact, based on a type of hydraulic motion platform originally designed for pilot training. A steadily turning airplane feels just like one flying straight; the coffee remains level in your cup, the stewardess stands upright in the aisle, even when the airplane is banked. The brain expects the eyes to resolve the inner ear's uncertainties, and so once a pilot is deprived of visual references he is helpless without some kind of artificial means of knowing which way is up.

That information comes from instruments containing gyroscopes, which hold their orientation in space as the airplane revolves around them. Airplanes use two basic kinds of gyros: the attitude indicator, or "artificial horizon," which presents a simplified picture of the airplane and the horizon ("attitude" is a pilot's term for the airplane's position -- nose high or low, banked, and so on); and the directional gyro, which tells which way the airplane is headed. There is also a backup attitude gyro called a turn-and-slip indicator. Gyros can be driven electrically or by an air pump on the engine; whichever power source the main attitude indicator uses, the turn-and-slip uses the other, so that a single failure won't deprive the pilot of all of his attitude information.

Flying by reference to gyro instruments isn't hard. Some beginners even find it easier than flying by reference to the outside world. It gets harder when you throw in turns and climbs and descents and navigational fixes and glideslopes and turbulence; but just keeping an airplane right side up or making gentle turns by reference to instruments is very easy.

Kennedy, like every student pilot, had already spent time flying by instruments alone. The FAA flight test that he took to get his private license includes some maneuvering while wearing a tunnellike visor that blocks your view of everything except the instrument panel. The intent of the requirement is that if a non-instrument-rated pilot accidentally flies into a cloud (or, for that matter, into a haze layer at night), he should have the ability to turn around and fly back out.

Much of the rest of instrument flying has nothing to do with staying upright, but rather with air-traffic control. Something must be done to keep blind-flying airplanes from running into one another. The current solution to the problem -- which has been in use, with various technical improvements, for more than half a century -- is to have controllers on the ground keep track of all flights, anticipate conflicts and tell pilots what to do to avoid them. When pilots work on their instrument ratings, they are mainly learning the very considerable complexities of taking off, navigating and landing within the air-traffic-control system, with visual references only at the very beginning and very end of the flight.

Controllers usually follow airplanes on radar screens, which show a two-dimensional map of the ground, with airplanes depicted as bright dashes moving across it. Each airplane's altitude is printed next to its dash or "target," and comes not from the radar itself but from a reporting device aboard the airplane. (Many airplanes also carry their own radar, but the purpose is to display weather, specifically heavy rain, not other airplanes on collision courses.) There is no evidence that air-traffic problems played a role in the Kennedy accident.

Sometimes ground controllers give pilots "vectors," that is, instructions to fly in a particular direction. Usually, however, pilots receive an altitude assignment and a "clearance" to a location, and then navigate by means of radio beacons on the ground or, increasingly of late, by means of GPS, the satellite-based positioning system also used in some cars. There are several types of ground-based radio-navigation systems and several kinds of airborne receivers, and they are used in various combinations for various purposes; there are voluminous regulations about what a pilot is to do while flying IFR (by "instrument flight rules"), and how and when he is to do it. The great bulk of the flight or simulator training â that pilots receive on the way to the instrument rating is devoted to navigational and procedural complications and emergencies, and to accurate execution of landing approaches, which often require staying within a few feet of the center line of a radio beam while descending, blind, to within a few seconds of touching down. But these are the extreme demands of flying, seldom encountered in life. One of the surprises that await instrument pilots once they get their ratings is how simple the actual practice is, compared with the preparation for it.

We hear that hazy conditions the night of the Kennedy flight called for instrument flying. Pilots use the terms "IFR conditions" or "IMC" ("instrument meteorological conditions") to describe weather that is too murky for "VFR" ("visual flight rules") flying. Usually, we just say "IFR" for everything: "Van Nuys is IFR." The rules defining when it's IFR and when it's VFR are complex, but generally it's IFR in the daytime when the visibility is less than three miles and/or there is cloud cover less than 1,000 feet above the ground, and at night when the visibility is less than five miles.

When pilots speak of "hard IFR," they mean the kind of weather in which you plunge into clouds just after takeoff, encounter a thunderstorm or two, or some freezing rain, and never see the ground until you break out 200 feet above the runway threshold on landing. Most IFR flying is not of that kind. A pilot may file an IFR flight plan and be continually in contact with ground controllers, yet only be in cloud during a small portion of a flight, or not at all. In any case, flight conditions when Kennedy departed were not IFR. Forecast visibility was a generous eight miles -- well above night VFR minimums.

In theory, an instrument-rated pilot is safer than a VFR-only one, because his choices are less dependent on the weather. But the instrument rating itself is a two-edged sword. Longtime Flying magazine editor and éminence grise Richard Collins spent years urging private pilots to get instrument ratings, on the theory that the number of VFR pilots going out on a limb in marginal weather -- one of the major causes of general aviation accidents -- would thereby be reduced. The Federal Aviation Agency joined the crusade by relaxing experience requirements for the rating. Lately, however, Collins has backpedaled; he has started to suspect that inexperienced or occasional instrument pilots flying in weather are just as much at risk as non-instrument pilots trying to stay out of it. Furthermore, instrument flying has its own special dangers. Icing and thunderstorms are the two biggest ones, but even experienced instrument pilots sometimes get disoriented and experience vertigo, overwhelming dizziness that undermines their confidence in their instruments. Sometimes pilots set radio frequencies incorrectly, or misread an altimeter, and end up flying into the ground. "Controlled flight into terrain" is a sufficiently common phenomenon that it has a nickname: Accident analysts call it "See-fit" (from the acronym CFIT).

Although keeping the airplane upright and headed in the right direction is a comparatively trivial task, it does require undivided attention for long periods. So practically all airplanes equipped for IFR flying have autopilots (traditionally, and ironically, nicknamed "George"), which do most of the actual instrument work. In practice, the majority of the human pilot's time aloft on an IFR flight is spent eavesdropping on sporadic communications between controllers and other pilots -- or, at night, on finding ways to stay awake. Only during the landing approach does the pilot become really busy.

Some pilots use their autopilots even for landing approaches, but many prefer to hand-fly the approaches in order to maintain their proficiency. Even those who hand-fly may use an instrument called a "flight director," which integrates functions of the attitude indicator, navigational radios and autopilot into a display that guides the pilot's every move with pointers that say, in effect, "Do this" and "Do that." Kennedy's plane had both a flight director and an autopilot, and one of the questions that National Transportation Safety Board (NTSB) investigators will ask is why they didn't suffice to keep the plane in the air.

Many commentators attributed Kennedy's decision to fly that night to an inherited propensity for risk taking. But his choice was not really so rash. Because the flight ended badly, some assume that it must have been unduly risky from the start; but that notion is both logically flawed and factually wrong. Every flight holds some danger or other. Usually the dangers do not materialize, but they are no less real -- potentially real -- for all that. The important point, ignored by many pundits, was that there was an out that night: If you lost sight of everything, you could always turn around and go back to the mainland.

It's possible that Kennedy flew into a layer of haze and panicked when he saw the scattered lights of Martha's Vineyard disappear in front of him. Perhaps sudden fright made him unable to use the ample means that the airplane provided for remaining upright and either reaching Martha's Vineyard or turning back. It's possible that he had an attack of vertigo. But it's also possible that an insidious autopilot failure, an air-pump malfunction or a gyro failure occurred, and that he didn't recognize it until too late.

Most of the six to nine months that the NTSB will spend investigating the accident will be given over to bureaucratic churning, but some of it will focus on determining, from traces of evidence in the wreckage, what went wrong. Until the NTSB publishes its findings (not that the NTSB is infallible, but it's the best we have), we should not stampede to make Kennedy the perpetrator of the accident rather than its victim. Out of respect for his memory, Kennedy should, for the time being, be presumed innocent.

 

Peter Garrison is a writer and pilot whose monthly column in Flying magazine, "Aftermath," analyzes airplane accidents.