A faulty repair appears to be largely to blame for a plane crash that killed Tahir Cheema, the founder and president of a locally based cargo airline, more than 17 months ago near St. Louis.
While a "factual" report issued by the National Transportation Safety Board does not identify a probable cause for the Nov. 30, 2004, crash near Chesterfield, Mo. that killed Mr. Cheema and a co-pilot, it shows that investigators focused on a system called the "elevator trim tab" that had just been repaired on the Hansa 320 aircraft that was to be flown from Spirit of St. Louis Airport to Toledo Express Airport.
Testing done on a Hansa 320 at Grand Aire's Toledo Express headquarters showed that when the controller for its elevator trim tab - part of a system that determines whether a plane pitches up or down or flies level - was rotated forward, it caused the tab to go into a position that would cause the aircraft to nose down.
But on the plane that crashed, similar motion of the controller moved the tab in such a way that the aircraft would nose up.
The report noted that the control cables for the elevator trim tab had been freshly replaced by a mechanic at Midcoast Aviation, a repair shop at Spirit of St. Louis Airport. The aircraft was not flown between the cable replacements and the crash flight.
Dick Williams, president of Aviation DataSource in Denver, said regardless of whether Mr. Cheema, who was piloting the fatal flight, was trying to go higher or lower, getting the opposite result from what he expected would have caused an immediate problem.
If the plane nosed down unexpectedly, a crash was imminent, he said, while if it nosed up unexpectedly, it could go into an aerodynamic stall that would cause it to lose airspeed.
"He doesn't have correct control of the pitch position, and he doesn't know why," he surmised.
The report also said Mr. Cheema needed to get the plane to Toledo that night to avoid the expense of obtaining a "check ride" coming due for him as a pilot of that aircraft model.
Mr. Cheema's "current" status as a certified Hansa 320 pilot expired the day of the crash.
Medical testing, meanwhile, found Mr. Cheema had diphenhydramine - the active ingredient in the cold medicine Benadryl - in his blood, lungs, and kidneys at the time of the crash.
"In therapeutic doses, the medication commonly results in drowsiness, and has measurable effects on performance of complex cognitive and motor tasks (e.g., flying an aircraft)," the safety board wrote.
Ted Lopatkiewicz, an NTSB spokesman, said agency officials would not elaborate on the report, since doing so would constitute analysis. A finding of "probable cause" for the crash could be issued by the end of this month, he said.
Mr. Cheema, 50, of Perrysburg, and co-pilot Eko Pinardi, 40, of Fort Wayne, Ind., died when the plane, which was being flown under a special "ferry permit," crashed two miles west of the airport on the edge of an island in the Missouri River.
According to an initial flight plan the NTSB cited, takeoff was originally scheduled for 3:30 p.m. St. Louis time for a 45-minute trip to Toledo. But Mr. Cheema postponed the departure several times - including one aborted takeoff when the plane's airspeed indicators didn't work - and the flight did not depart until 7:55 p.m. The plane crashed less than a minute after takeoff.
The tardy departure meant the flight was in violation of Federal Aviation Administration regulations. Mr. Pinardi had no training or experience flying a Hansa 320, which meant he was qualified to be second-in-command only during a daytime flight, the safety board reported.
The delays also meant that the flight took off in bad weather. Rain was falling and the temperature was 36 degrees at 7:28 p.m. As of the next report at 8:02 p.m., the rain had changed to light snow, but an airport official told investigators that there was no indication of any snow or ice sticking to surfaces at the time.
Mr. Williams said the combination of negative factors - the recent repair, the delays and bad weather, Mr. Cheema's apparent need to take cold medicine - suggest the flight was unwise.
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