A week after Comair Flight 3272 crashed outside Detroit, medical examiners have completed identification of all 29 people aboard and have released the remains to their families, Monroe County Medical Examiner David Lieberman said Wednesday.
Funeral arrangements have been made for Pilot Dann Carlsen of Grant County, Ky., and passenger Dexter Adams of Paddock Hills.
Meanwhile, in Monroe County, ground crews no longer hampered by bitter weather are nearing completion of wreckage recovery, said National Transportation Safety Board (NTSB) spokesman Paul Schlamm.
Investigators continue to search for a reason for the crash of the Cincinnati-to-Detroit flight Jan. 9.
No factors have been ruled out as the cause, Mr. Schlamm said, including mechanical failure, pilot error or weather conditions.
At 38 seconds before the crash, the Embraer Brasilia 120 turboprop was flying at 188 mph. Seventeen seconds before the crash, the plane was in a turn and the air speed had dropped to 167 mph. That's when the plane's autopilot deactivated automatically and a stall warning went off, the plane's flight data recorder revealed. Investigators are looking at whether the plane was flying too slowly to maintain controlled flight.
Factors that could have contributed to the drop in speed could include a build-up of ice on one or both wings, pilot error, a malfunction in the autopilot or other controls, aviation experts say - or a combination of any of the above.
In an airplane stall, the wings lose their ability to lift the plane, typically because of a disruption in smooth air flow over the wing. One possible cause of disruption is a buildup of ice on the wing. A stall does not necessarily mean the engine ceased to operate.
Flight 3272 crashed into a
snow-covered field 45 miles south of Detroit, killing all 26 passengers and three crew members aboard. Pilots in the area of the crash had earlier reported icy conditions.
''If it's icy, you can turn off the autopilot, but it probably isn't written anywhere,'' said Robert Benson, an NTSB investigator who is currently assigned to the crash of TWA Flight 800 off Long Island, N.Y. ''Normally, if a pilot is aware of icing up, he can maintain higher air speed, limit angle of banks and turns, descend or climb.''
Mr. Benson said there are three typical indicators of ice buildup - the pilot sees ice on the wings, feels turbulence, or notices a loss of speed.
NTSB officials say only that the cockpit voice recorder did not pick up any reference from the crew to a system problem.
There are two principal instruments in the cockpit - a primary altimeter and an attitude direction indicator - which can be adversely affected by a malfunction in the electrical system, Mr. Benson said. The NTSB has not indicated whether such an event took place on Flight 3272.
A third indicator, a standby
air-speed indicator, is independent from the first two, so it is virtually impossible that all three could give identical - incorrect - readings, Mr. Benson said. It is possible the
air-speed indicators were working properly but that pilots simply did not monitor them closely enough, he said.
''If distracted, if you get busy enough, it can happen,'' he said.
Another likely focus for investigators is the autopilot's role, some experts said.
At the time the airplane entered its final left turn, it was flying on autopilot. After the turn started, the autopilot tried to pull the controls back to the right.
When the stall warning sounded, the autopilot disengaged - whether the pilots switched it off is unclear - and the plane immediately starting diving.
Experts repeatedly recalled the 1994 crash of an ATR-72 plane near Roselawn, Ind.
In that accident, the plane's autopilot was compensating for ice dragging on its wings. The pilot apparently didn't notice the icing; when the autopilot was turned off, the plane plunged.
Services announced
Funeral services for pilot Dann Carlsen, 42, will be held at 1 p.m. Jan. 23 at Millendorf-Bullock Funeral Home, Hebron. There will be no visitation.
Services for passenger Dexter Adams of Paddock Hills will be 10 a.m. Saturday at Southern Missionary Baptist Church, Avondale. There will be no visitation.
The Associated Press contributed to this report.
PROFILES OF VICTIMS
SEVEN DAYS OF CRASH COVERAGE
