The Optimist's Approach
By Peter Garrison
November 2008
On Christmas night, 2006, it was foggy in Lawrenceville, Georgia. Briscoe Field was reporting half a mile visibility in fog, with the ceiling at 100 feet, when a Cessna 414A arrived from Florida on an instrument flight plan.
The 44-year-old commercial pilot had logged over 400 of his 632 hours in the airplane in which his life and those of his two passengers were shortly to end. His actual instrument time was 26.4 hours, his simulated instrument time 56.3. He had logged 142 hours at night. He was comparatively inexperienced, but current, qualified and legal. Despite the festive date he was not, as toxicology tests would later establish, under the influence of alcohol.
As the pilot approached Lawrenceville the controller advised him of the weather, which was below the airport minimums of 200 and one half. The pilot elected to attempt the ILS Runway 25 approach, as he was entitled to do: The criteria for landing are expressed in the FAR as "flight visibility," because it is understood that what the pilot sees on final approach is not necessarily the same thing as is seen from the tower or from some other weather observation point. The pilot is on his honor not to descend below the minimum altitude unless he has the runway or its lights in sight.
The pilot missed the approach; but he reported to the controller that he had caught sight of the airport as he passed over it and wanted to try again. The controller vectored him back around to the approach course and repeated the current weather conditions.
On the second approach, the tower advised the pilot that he was drifting to the left of the extended runway centerline. The pilot acknowledged. Shortly after, the tower controller saw a bright orange glow beside the approach end of the runway. He tried without success to contact the 414. It had crashed into an asphalt plant, clipping the tops of trees and striking a gravel berm before eventually coming to a stop 1,100 feet south of the runway, heavily fragmented, amidst the machinery of a rock crusher.
The NTSB neatly, if unhelpfully, summed up the probable cause: "The pilot's failure to follow the instrument approach procedure [and his] descent below the prescribed decision height altitude."
This is the kind of accident that the newspapers will describe with some such phrase as, "The airplane crashed while attempting to land in fog." The image conveyed to the lay reader is of the pilot feeling his way toward the airport and inadvertently bumping into something, just as a driver, creeping forward in dense fog and darkness, might, in a moment of divided attention, collide with an inconveniently situated tree.
To an instrument pilot, the picture is more complex. An instrument approach is not a matter of feeling one's way. It is a mechanical procedure which, if executed rigidly, will end either in a safe landing or in a safe abandonment of the attempt. It goes without saying that if you follow the instrument approach procedure to the letter, you will not hit the ground. So how does it happen that pilots, even ones flying precision approaches in which both altitude and lateral position are continually displayed, so often crash in the vicinity of the approach end of the runway, particularly at night?
You seldom learn exactly what happened on a particular flight -- unless the pilot survives -- but you can imagine a plausible scenario. On the first approach, the pilot stops descending at the decision height and overflies the runway. Looking down, he glimpses the runway lights, and possibly, if the fog is spotty enough, even discerns illuminated features on the ground -- a pool of light around a windsock or in front of a building, airplanes parked on the ramp. After all, these things are only 200 feet away, and the visibility under the overcast is half a mile. It appears that with a little luck he ought to be able to land. So he comes around for another try.
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