Flying - - CONTENTS - By Peter Gar­ri­son

Per­sis­tence, or what you might call ob­sti­nacy

It wasn’t great fly­ing weather. A sig­met called for nu­mer­ous embed­ded thun­der­storms with tops to 35,000 feet, pos­si­ble tor­na­does, 2-inch hail and 70-knot gusts. The route of the pro­posed flight from New Or­leans to Sarasota, Florida, ran along the mid­dle of the squall line, which ex­tended from Texas to the At­lantic and was mov­ing east­ward at a brisk 30 knots.

The pi­lot had ob­tained a brief­ing the pre­vi­ous even­ing and had filed an IFR flight plan. He got a se­cond brief­ing in the morn­ing. When the pi­lot, his wife and an­other cou­ple ar­rived at New Or­leans Lake­front Air­port, nu­mer­ous thun­der­storms were in the vicin­ity. Some­one asked the pi­lot why they did not wait un­til to­mor­row, when the weather would be bet­ter. “It’s no prob­lem,” the pi­lot said. “I can han­dle it.”

Level at FL 210, the pi­lot re­ported to ATC that it was “a lit­tle rough.” Five min­utes later, how­ever, he was back with a more se­ri­ous prob­lem: He was hav­ing trou­ble with his gy­ros, and was de­scend­ing.

The air­plane, a Cessna P210R, was equipped with a “known ic­ing” pack­age that in­cluded two vac­uum pumps, ei­ther of which could drive the in­stru­ments. Should one of them fail, one of two but­tons on the suc­tion gauge would pop out, show­ing red. It was also equipped, in­ci­den­tally, with radar and a Storm­scope.

Three min­utes later, the pi­lot re­ported that all of the air­plane’s gy­ros were out and he was de­scend­ing in an ef­fort to find VFR con­di­tions. But there were no VFR con­di­tions to be found. The pi­lot then said he would level off at 11,000. Seven min­utes had now passed since the first re­port of gyro trou­ble. The P210 re­mained in radar con­tact for an­other five min­utes but was not heard from again. It finally dis­in­te­grated in flight, scat­ter­ing wreck­age over an area 4½ miles long near Mo­bile, Alabama.

In­ves­ti­ga­tors con­cluded from in­spect­ing the vac­uum pumps that the left one had failed but the right had not. The at­ti­tude gyro ap­peared to have failed as well — a spin­ning gyro makes scuff marks on its hous­ing in a crash, and there were none — leav­ing the pi­lot with only the elec­tric turn and bank in­di­ca­tor, the di­rec­tional gyro and the wet com­pass for guid­ance. Si­mul­ta­ne­ous fail­ure of the at­ti­tude gyro and a vac­uum pump was astro­nom­i­cally im­prob­a­ble, but at least it ex­plained why the pi­lot be­lieved that both vac­uum pumps had failed at once — an equally un­likely event. Al­though it should, in prin­ci­ple, be pos­si­ble to fly solely by ref­er­ence to the turn and bank in­di­ca­tor, pi­lots who have to


do so for a long time of­ten end by los­ing con­trol.

The Na­tional Trans­porta­tion Safety Board in­cluded among fac­tors re­lated to the ac­ci­dent “the pi­lot’s ... over­con­fi­dence in him­self and the air­plane.”

The NTSB re­port in­cluded an ac­count of a re­cent in­ci­dent from the pi­lot’s home base in New York, seem­ingly in­tended to sug­gest that his over­con­fi­dence bordered on pig­head­ed­ness. The pi­lot had asked his FBO to have his air­plane ready in the morn­ing, but 6 inches of snow fell dur­ing the night and the ramp and taxi­ways were blocked. Freez­ing rain was fall­ing heav­ily, and al­though many jets and tur­bo­props were based at the air­port, no air­craft were ar­riv­ing or depart­ing. Ap­pear­ing at the FBO, the pi­lot was in­censed to find that his air­plane was not ready to go. Var­i­ous peo­ple, in­clud­ing his wife, tried to con­vince him that the ice-ac­cu­mu­la­tion rate was too high for safety. He in­sisted, how­ever, that his air­plane was cer­ti­fied for flight into known ic­ing con­di­tions, and de­manded that the ramp be cleared for him. Af­ter this was done, he tax­ied out, bogged down in snow af­ter 100 yards, and was finally forced to aban­don his planned trip.

This story, while an in­ter­est­ing il­lus­tra­tion of a cer­tain per­son­al­ity type in ac­tion, would have been more ger­mane if the cause of the in-flight breakup had been ex­treme tur­bu­lence, de­struc­tive hail or a tor­nado. Since the cause seemed to be mere equip­ment fail­ure, it could equally well have hap­pened on any flight in IMC with tur­bu­lence, with or with­out thun­der­storms.

The 4,300-hour pi­lot of a Cessna 310 dis­played a dif­fer­ent sort of per­sis­tence. Re­turn­ing home near mid­night from a busi­ness trip, he found ground fog cov­er­ing his home air­port. He flew an ap­proach, missed, and told the con­troller he would give it one more try.

The field el­e­va­tion was 1,474 feet, and the min­i­mum de­scent al­ti­tude 1,840. On the first ap­proach, the pi­lot de­scended to 1,700 feet be­fore go­ing missed; on the se­cond, radar tracked him down to 1,500 feet. The 310 crashed in a flat, open pas­ture, about three-quar­ters of a mile short of the run­way. The air­plane en­coun­tered the ground at a shal­low an­gle and slid or skipped to a stop, re­main­ing largely in­tact, but the pi­lot died of mas­sive head in­juries. Cu­ri­ously, the land­ing gear and flaps were found in the re­tracted po­si­tion.

Ground fog can con­sist of a thin layer on the sur­face with clear air above it. Thus, de­scend­ing be­low min­i­mums is not quite the same as when solid clouds come down to within a cou­ple of hun­dred feet of the sur­face.

The pi­lot’s wife at­trib­uted his ac­tions to a strong de­sire to be back home with his fam­ily. The NTSB, how­ever, took a dif­fer­ent view. It found that on his ap­pli­ca­tion for a se­cond-class med­i­cal seven months be­fore the ac­ci­dent, he had given neg­a­tive an­swers to all ques­tions re­gard­ing use of med­i­ca­tions, med­i­cal con­di­tions and vis­its with doc­tors. But the post-mortem tox­i­col­ogy turned up a whole phar­ma­copeia in the pi­lot’s bod­ily flu­ids. In­ves­ti­ga­tors sub­se­quently ob­tained his per­sonal med­i­cal records, which re­vealed that he had a life­long history of mi­graine headaches oc­cur­ring al­most daily and last­ing more than four hours, for which he had been pre­scribed, and was still us­ing, a for­mi­da­ble va­ri­ety of med­i­ca­tions, both in­gested and in­jected.

The NTSB at­trib­uted the ac­ci­dent to the pi­lot’s im­pair­ment by ei­ther med­i­ca­tions or a mi­graine, or both. The ev­i­dence for this con­clu­sion was only cir­cum­stan­tial; he had ev­i­dently flown for years with the same im­pair­ments, and, in the absence of the med­i­cal records, the NTSB might in­stead have blamed fa­tigue.

What is strik­ing about this story is not the ac­ci­dent it­self, which is of a com­mon enough kind, but the pi­lot’s prac­tice of con­ceal­ing his med­i­cal history from the FAA. Not that it was in any way sur­pris­ing. He op­er­ated a busi­ness that re­quired him to travel fre­quently. He was also a part­time flight in­struc­tor. Ob­vi­ously, some­one whose liveli­hood de­pends on his fly­ing might not give truth­ful an­swers about dis­qual­i­fy­ing med­i­cal con­di­tions.

But what does the pi­lot tell him­self?

I sup­pose it is what pi­lots tell them­selves about all sorts of other haz­ardous sit­u­a­tions to which they ex­pose them­selves (and not just pi­lots — many peo­ple nor­mal­ize one sort of haz­ardous ac­tiv­ity or an­other in the same way). We ex­trap­o­late from the past. If we have made a habit of scud-run­ning, we note that de­spite the re­puted risks of the ac­tiv­ity, we are still alive. If we have de­scended be­low min­i­mums be­fore and not crashed, we rea­son that we can do it again. Ex­pe­ri­ence is a more per­sua­sive teacher than a rule book.

And so the pi­lot is un­daunted by his daily mi­graines and the salad of poly­syl­labic painkillers that he uses to con­trol them. He has thou­sands of hours. He knows what he’s do­ing; fly­ing isn’t that dif­fi­cult, when you’re good at it. And then, one day, he de­scends into ground fog with gear and flaps up, and hits the ground.

How can that be? He would never have be­lieved it.


Newspapers in English

Newspapers from USA

© PressReader. All rights reserved.