LARENCE, N.Y. — Investigators finished gathering human remains at the site of last week's catastrophic plane crash outside Buffalo and turned their attention to analyzing the weather, data from the scene and black-box recorders, the crew and accounts from other pilots who flew nearby on the night of the accident.
The National Transportation Safety Board will also examine whether the pilot of Continental Connection Flight 3407 overreacted when an automatic safety system sensed the plane was slowing down dangerously, said Lorenda Ward, NTSB's chief investigator.
The pilot pulled back on the plane's controls after the safety system tried to push the nose downward to gain speed and avoid losing lift. Ward said one of many possibilities is the pilot pulled back too hard, bringing the plane's nose too high up in an attempt to prevent the stall and dooming the aircraft.
Early Wednesday, workers were removing the plane's enormous tail from the crash scene as well as any other remaining debris in an attempt to complete the cleanup ahead of a snowstorm forecast to bring a few inches of snow to the Buffalo area, Ward said.
Keith Holloway, an NTSB spokesman, said it is still too early to definitively say what brought the plane down.
"We have not concluded anything," he said Wednesday morning.
Flight 3407 was only about 1,600 feet above the ground at the time and aviation safety experts said this week that it might have been too low to dive out of a stall condition.
"Things happened so quickly, and they were so low to the ground, that it would not have mattered if Chuck Yeager and Neil Armstrong were flying the plane; there wouldn't have been a different outcome," said Kirk Koenig, president of Expert Aviation Consulting of Indianapolis and a commercial aviation pilot for 25 years.
The pilot's actions are being scrutinized to determine whether he could have acted differently to prevent the plane from crashing onto a home on Thursday. All 49 people on board the aircraft and one person on the ground were killed.
So far, the NTSB has not found anything mechanically wrong with the plane.
However, the pilot did not disengage the autopilot after encountering what was noted to be "significant ice" — disregarding recommendations from the NTSB and his own airline.
Ward said the NTSB probe will also look at whether this recommendation should be a regulation, something NTSB has supported for years.
In addition, as in every crash, Capt. Marvin Renslow's experience and training will be closely studied.
Renslow had amassed 110 hours of flying experience on the Bombardier Dash 8 Q400. He also had thousands of hours flying a similar, smaller turboprop plane, which experts say would have prepared him for handling the aircraft in icy weather.
The NTSB will look into the type of training the pilots received, how they performed, how many hours they flew in the seven days before the crash, how much rest they had and what they did in the 72 hours before the accident, Chealander said. That includes a look at whether they drank any alcohol or took drugs.
Another NTSB investigator will study whether the wintry weather played a role in the crash, while still others will interview pilots who recently flew with Renslow, 47, of Tampa, Fla., and the first officer, Rebecca Lynne Shaw, 24, of Seattle.
The full investigation is expected to last at least a year.
The flight, operated by Colgan Air, was about six miles from Buffalo Niagara International Airport and on autopilot when it became uncontrollable, pitching sharply up and down and side to side before smashing into the home and bursting into flames.
NTSB investigators have focused on the icy conditions in which the plane was flying, noting the crew took a cautious approach by engaging deicing equipment 11 minutes after leaving Newark, N.J. However, investigators have stopped short of saying ice caused the crash, noting there are endless possibilities.
Colgan Air, based in Manassas, Va., did not return a call Tuesday seeking comment on training procedures. Renslow had 3,000 hours of flying experience with Colgan over 3 1/2 years, which is nearly the maximum a pilot can fly over that period of time under government regulations.
Johnny Summers, a pilot on a Boeing 737 who also has flown turboprop planes, said flying in ice is fairly routine. Planes are designed for it, and pilots train for it.
Summers recalled that a few years ago, while flying a Twin Otter into Colorado Springs, he was forced to land because of severe ice. The ice made the plane too heavy to climb to a higher altitude to escape the bad weather, he said.
He could not remember whether the crew turned off the autopilot but said all deicing and anti-icing equipment was immediately turned on. That aircraft was a twin-engine turboprop that seats eight, while the Dash 8 seats 74.
"I wasn't nervous about it," Summers said. "It's not that spooky of a thing."