Tape: Plane Made Sudden Dive in Crash

Sounds recorded in the cockpit show that a commuter plane leveled off normally at 4,000 feet as it prepared to land and then suddenly plunged earthward and crashed into the ground, a member of the National Transportation Safety Board said Saturday night.

John Hammerschmidt, who is heading the investigation of Thursday’s crash that killed all 29 aboard Comair’s Flight 3272, declined to characterize those sounds. He would not say whether they were the voices of the cockpit crew, mechanical noises or a combination of the two.

“We’re still trying to get a handle on what happened,” he said at a news briefing here.

Hammerschmidt said that after listening briefly to the recording from one of the so-called “black boxes” recovered from the wreckage, experts at the NTSB laboratory in Washington concluded that most of the scheduled flight from Cincinnati to Detroit was “uneventful, routine, orderly and businesslike.”

He said that as the twin-engine turboprop began descending toward Detroit Metropolitan Airport in a light snowstorm, the cockpit crew complied with air traffic control instructions to descend from an altitude of 7,000 feet.

“Approximately one minute after leveling off at 4,000 feet, an event took place,” Hammerschmidt said. “Normal operations ceased, and the airplane crashed shortly thereafter.”

Asked for a description of the “event,” Hammerschmidt said the lab experts “could not be definitive.”

“I am not sure that they understand it at this time,” he said. “And all we know is what they’ve told us.”

Hammerschmidt said data from the plane’s other black box--the flight data recorder--have yet to be analyzed. He said analysis of the data is expected to shed considerably more light on what happened to Flight 3272. Further studies of the cockpit voice recording also should help, officials said.

Investigators are known to be focusing on the possibility that ice accumulated on the plane, overburdening the aircraft and disrupting the smooth flow of air over the wings.

A number of pilots in the area reported icing conditions at the time; the cockpit voice recorder shows that the pilots of Flight 3272 were aware of the dangerous weather conditions and had activated the plane’s de-icing systems.

Hammerschmidt said seven eyewitnesses, who were interviewed Saturday, agreed that the plane seemed to level off without difficulty, then began to wobble and roll. He said they all agreed that Flight 3272 appeared to stabilize momentarily, “and then the nose abruptly pitched down and the plane descended vertically to the ground.”

Aviators said these motions are consistent with a stall brought on by excessive icing.

On the other hand, crews that had flown the plane earlier on Thursday told NTSB investigators that the Embraer 120’s de-icing systems had appeared to be working properly. Fellow aviators described the cockpit crew of Flight 3272 as careful, competent pilots.

Air traffic controllers said the cockpit crew reacted normally and promptly to all instructions.

During the nine hours of bleary daylight here Saturday, recovery crews continued the grim, arduous task of retrieving fragmented human remains and shattered wreckage from a stubbled farm field about 18 miles southwest of the airfield in Detroit.

The weather had improved, but only slightly. Temperatures hovered in the teens, and winds gusting at up to 20 mph lashed chilled recovery personnel with biting streams of drifting snow.

About 30 to 50 men from the NTSB and local law enforcement agencies--gloved, booted and bundled in heavy winter clothing--braved the bitter weather for a second day on Saturday.

As it had on Friday, a windchill factor that dipped well below zero limited work shifts to 15 minutes.

Half a mile downstream from the River Raisin, the NTSB established its command post in a small brick schoolhouse erected in 1868. It’s the site of the first public school in Michigan, a log cabin built by settlers in 1828.