Other possible explanations are that the aircraft was spinning or flipped upon impact.
Flight data showed the plane's safety systems warned the pilot that the aircraft was perilously close to losing lift and plummeting from the sky. The ensuing crash killed 49 people on the plane and one in the house.
Continental Connection Flight 3407 was cleared to land on a runway pointing to the southwest, but it crashed with its nose pointed northeast, said Steve Chealander, a National Transportation Safety Board member.
The Newark, N.J.-to-Buffalo flight didn't nose-dive into the house, as initially reported by some witnesses, Chealander said. It will take as many as four days to remove human remains from the site, which he called an "excavation."
"Keep in mind, there's an airplane that fell on top of a house, and they're now intermingled," he said.
The plane - on its descent to Buffalo Niagara International Airport in a light snow and mist - plunged suddenly about six miles shy of the runway and exploded.
A "stick shaker" and "stick pusher" mechanism had activated to warn Capt. Marvin Renslow that the plane was about to lose aerodynamic lift, a condition called a stall. When the "stick pusher" engaged, it would have pointed the nose of the plane toward the ground to try to increase lift.
Crash investigators picked through incinerated wreckage Saturday, gathering evidence to determine what brought down the plane. Icing on the aircraft is suspected to have played a role, but officials have stopped short of calling that the cause.
Chealander said indicators lights showed the deicing equipment was working and that investigators who examined both engines said it appears they were working normally at the time of the crash. Experts were analyzing data from the black boxes, including statements by crew members about a buildup of ice on the wings and windshield of the plane, Chealander said.
If a deicing system isn't working, guidelines from the Aircraft Owners and Pilots Association Air Safety Foundation say pilots can take a number of steps, including changing speed, pulling the nose up or down, or trying a 180-degree turn.
On Friday, U.S. Sen. Robert Menendez, D-N.J., said Transportation Secretary Ray LaHood had told him he believes the aircraft made a 180-degree turn at 5,000 feet.
But there could other explanations for why the plane was facing the wrong way.
Chealander said the NTSB would use data on the black boxes to determine whether the plane was in a flat spin before it crashed. Flight data indicated "severe" pitching and rolling before impact, so the violent nature of the crash also could have turned the aircraft around.
Other aircraft in the area Thursday night told air traffic controllers they also experienced icing around the time that the plane went down.
Icing is one of several elements being examined by investigators, Chealander said, adding that a full report will probably take a year.
DNA and dental records will be used to identify the bodies, he said.
One aspect of the investigation will focus on the crew, how they were trained and whether they had enough time to rest between flights. Other investigators focused on the weather, the mechanics of the plane and whether the engine, wings and various mechanics of the plane operated as they were designed to.
Initial visual inspection of the engines indicates they were working properly, Chealander said.
----
Associated Press writers William Kates, Larry Neumeister, Ramit Plushnick-Masti, Carolyn Thompson and John Wawrow contributed to this report.
CLICK HERE to follow Action News on Twitter
CLICK HERE to get Action News on your website
CLICK HERE to find Action News on Facebook
