The single pilot of a single-engine Pilatus PC-12 turboprop enroute from St John's.

The single pilot of a single-engine Pilatus PC-12 turboprop enroute from St John's, Newfoundland, to simpleton Bay, Labrador, thought the engine reasonable oil pressure light was a faulty indication, in the way that he did not immediately get back to St. John's, some 39 NM away. Bad decision, declares the Transportation Safety Board (TSB) of Canada in its recently-issued final report of the May, 1998 crash of the PC-12 into a moss as the pilot, forced to enclose down the violently vibrating engine, was attempting to glide into a divert airfield. The pilot failed to recognize an "error trap," the TSB intoned (an error trap is an unsafe action taken as a come of a wrongful assumption, in this case that the oil squeezing warning system was faulty, not the engine). Imagine as it is an "error trap" in the ETOPS scenarios described lately (see ASW, April 3).

Give the pilot credit for airmanship. He made an unpowered landing with the windscreen masked in engine oil on the outside and with condensation upon the inside (he sideslipped to papal court out the side window). Three of the ten aboard were injured (including the pilot), moreover there were no deaths in a crash-landing that totaled the aircraft.

The TSB's of the highest order report raises important questions about the adequacy of extremity battery power for all aircraft. It noted that the PC-12's extremity battery power for essential instruments was dutiful for 31 minutes, but attempting to relight the engine, or use of electric windshield heat or the use of a landing light at night would place a large draw forward the battery. The current drain would remodel battery time to just 225 minutes, which is les than the 28 minutes it would take to issue a gliding (unpowered) descent from 25000 feet

For the glutted text of the report, go on foot to the TSB website at http://www.tsb.gc.ca ; click upon aviation, select 1998 and schedule to report number A98A0067.

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