Investigators say the Canadian-made plane that crashed into a home outside of Buffalo landed flat on the house, and was pointed in the opposite direction of the airport where it was supposed to land.

National Transport Safety Board spokesperson Steve Chealander said that the wreckage of Continental Connection Flight 3407 indicates the plane did not nose-dive into the house as previously thought.

The flight was supposed to land on a southwest runway, but crashed with the nose facing northeast.

Investigators say it could take at least a year to understand why the commuter airliner crashed, killing 49 people on the plane and another victim on the ground.

Workers began sifting through shattered pieces of the plane and removing victims' remains early Saturday, a process that could take about three or four days, said Chealander.

But it could take investigators another 12 months or more to piece together exactly what happened as the plane approached the Buffalo airport.

"There's a lot of the airplane there, it's all there," Chealander said Saturday afternoon on Â鶹´«Ã½net. "It may be in pieces but we take each and every piece seriously, take it out and examine everything that we can possibly examine."

The flight crew began noticing significant buildup of ice on the wings and windshield not long before the plane slammed into a house in Clarence Center, a bedroom community just outside of Buffalo.

Investigators say that that the plane's deicers were turned on and both prop engines appear to have been functioning properly.

The NTSB has said that the aircraft underwent "severe" pitch and roll after the flaps were engaged in preparation for a landing. Investigators said Saturday the autopilot was disengaged at that time. The plane crashed within a minute after the flaps were engaged.

Earlier Saturday, CTV's John Vennavally-Rao said investigators told the media that identifying the victims may be difficult, given the severity of the crash.

"The crash happened with such an impact and there was so much fire that identification may be an issue," Vennavally-Rao told Â鶹´«Ã½net early Saturday morning.

According to Chealander, NTSB staff brief victims' relatives several times a day on the status of their investigation and their search for remains.

NTSB, Red Cross and FBI staffers are all on hand to help with the investigation, Chealander said.

Investigators have examined data from the plane's instruments and listened to the last communication from the flight's pilot and co-pilot in their effort to determine the cause of the crash.

The flight crew began noticing significant buildup of ice on the wings and windshield not long before the plane slammed into a house in Clarence Center, a bedroom community just outside of Buffalo.

Canadian, genocide expert among dead

In addition to killing all 49 people on board the plane, the crash killed one resident of the house. Two women escaped the home, which burned for hours, making it too hot for rescue crews to begin removing the victims from the scene.

Canadian Don McDonald of Fort Erie, Ont., was among those killed in the crash.

Also among the victims was Beverly Eckert, who became an outspoken advocate for families of the victims of 9-11 after her husband was killed at the World Trade Center, as well as Alison Des Forges, one of the world's top researchers into the Rwandan genocide.

Flight 3407 was travelling from Newark, N.J. to Buffalo and went down about eight kilometres short of the airport.

Weather conditions included light snow and mist, conditions that increase the risk for ice buildup, which can severely hamper the pilot's ability to handle the plane.

However, Chealander said that ice is only one of a number of potential causes that investigators will be looking at in the coming weeks and months.

"We are going to be looking at every aspect of this flight, from an operational standpoint, from a survivability standpoint, from a maintenance standpoint, the human performance standpoint," Chealander said. "We have groups that are focused on all those different areas."

Chealander confirmed that the NTSB has long been advocating for improved regulations for deicing.

"We don't like the progress that's taken place right now," Chealander told reporters earlier Saturday. "It's something that requires constant focus."

Smaller planes, such as the Dash 8, use a system of pneumatic de-icing boots, which are essentially rubber membranes that stretch over the surface of the wings. The boots are filled with compressed air to crack ice as it appears, but are only turned on after ice starts to form, according to Chealander.

After a similar jet crashed in Indiana 15 years ago due to ice, the NTSB recommended that the boots be turned on before ice starts forming on the wings, but the Federal Aviation Administration has not adopted the recommendation.

According to the plane's black box recording, the flight crew began to discuss "significant ice buildup" on the windshield and wings at an altitude of 11,000 feet, Chealander said Friday.

Before Thursday, the plane, a Canadian-made Bombardier Q400, had never been involved in a crash.

The 74-seat plane was operated by Colgan Air, an airline based in Manassas, Va.

There are more than 200 of the planes in service around the world, operated by about 30 different carriers.

With files from The Associated Press