The Folly of Fools by Robert Trivers

Author:Robert Trivers
Language: eng
Format: mobi, epub, pdf
Publisher: Basic Books
Published: 2011-10-17T04:00:00+00:00

ICE OVERPOWERS THE PILOTS; AIRLINES OVERPOWER THE FAA

Ice poses a special problem for airplanes. Ice buildup on the wings increases the plane’s weight while changing the pattern of airflow over both the main wings and the small rear control wings. This reduces lift and in some cases results in rapid loss of control, signaled by a sudden pitch and a sharp roll to one side. The controls move on their own, sometimes overpowering counterefforts by the pilots. Commuter planes are especially vulnerable because they commonly fly at lower altitudes, such as ten thousand feet, at which drizzling ice is more common. When icing results in loss of control, the plane turns over and heads straight to the ground.

To take an example, on October 31, 1994, American Eagle Flight 4184 from Indianapolis had been holding at ten thousand feet in a cold drizzle for thirty-two minutes with its de-icing boot raised (to break some of the ice above it), when it was cleared by Chicago air traffic controllers to descend to eight thousand feet in preparation for landing. Unknown to the pilots, a dangerous ridge of ice had built up on the wings, probably just behind the de-icing boot, so that as the pilots dipped down, they almost immediately lost control. The plane’s controls moved on their own but on the right wing only, immediately tilting the plane almost perpendicular to the ground. The pilots managed to partly reverse the roll before the (top-heavy) plane flipped upside down and hit the ground at a 45-degree angle in a violent impact that left few recognizable pieces, including any of the sixty-eight people aboard.

This was an accident that did not need to happen. This kind of airplane (ATR 42 or 72 turboprops) had a long history of alarming behavior under icing conditions, including twenty near-fatal losses of control under icing conditions and one crash in the Alps in 1987 that killed thirty-seven people. Yet the problem kept recurring because safety recommendations were met by strong resistance from the airlines—which would have to pay for the necessary design changes—and the FAA ended up acting like a biased referee, approving relatively inexpensive patches that probably reduced (at least slightly) the chance of another crash but did not deal with the problem directly. As one expert put it, “Until the blood gets deep enough, there is a tendency to ignore a problem or live with it.” To wait until after a crash to institute even modest safety improvements is known as tombstone technology. The regulators and airline executives are, in effect, conscious of the personal cost—immediate cost to the airlines in mandated repairs and bureaucratic cost to any regulator seen as unfriendly to the airlines—while being unconscious of the cost to passengers.

In the United States, the NTSB analyzes the causes of an airline disaster, relying on a series of objective data, cockpit and flight recorders, damage to aircraft, etc., to determine cause and then makes obvious recommendations. The theory is that this relatively modest investment in safety will pay for itself in future airplane design and pilot training to minimize accidents.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.