Hope To Complete On-Scene Investigation By Wednesday

As family members of the victims of Continental Flight 3407 walked Monday near the site of last week's accident in Clarence Center, NY, investigators with the National Transportation Safety Board pressed on with their investigation into what brought down the Bombardier Q400 turboprop with 49 people onboard.

The New York Times reports that, in particular, investigators plan to ask other pilots who flew in the area about icing conditions around the time the airliner crashed on approach to Buffalo Niagara International Airport last Thursday. While early speculation has focused on icing as a possible cause of the crash -- and evidence seems to point in that direction -- there were few if any reports of the kind of severe icing that could have brought the aircraft down from other pilots.

NTSB spokesman Steven Chealander told reporters Monday that so far, investigators have also discovered no mention of severe icing on tapes from the accident aircraft's cockpit voice recorder. As ANN reported, the CVR did record the pilots discussing "significant" ice buildup on the plane's wings and windscreen during the initial descent out of 11,000 feet, but that was several minutes before the airliner crashed.

Chealander noted that so far, other pilots have made mention of "moderate" ice buildup while flying south of Buffalo on the night of February 12. Another Colgan Air Q400, flying the same route out of Newark as Flight 3407, landed in Buffalo without incident 27 minutes after the accident.

Icing conditions are known to be problematic, and fast-moving. A region experiencing severe icing conditions can clear within minutes, due to changes in precipitation, moisture content of the air and temperature. There's also the question of semantics... of how one pilot's report of "moderate" ice compares with another's analysis of the situation.

With information obtained from the Q400's flight data recorder, investigators have mapped out what likely occurred during the flight's final seconds. As the plane continued on autopilot to the KLUMP Initial Approach Fix for runway 23 at BUF, the flight crew lowered the aircraft's landing gear, and 20 second later the first 15 degrees of flaps were selected.

Moments after the flaps lowered, the aircraft's stick shaker and pusher activated, signaling an imminent aerodynamic stall. That would have also disconnected the aircraft's autopilot. The aircraft's nose then pitched up 31 degrees, then down at a 45 degree angle. As that occurred, the aircraft rolled left 46 degrees, then right 105 degrees.

Flight 3407 impacted a residential area about 4.4 miles short of the runway at BUF, in what investigators have described as a nearly flat attitude with little forward motion. Radar returns indicate the aircraft fell from 1,800' MSL to 1,000' within five seconds, at which time the aircraft disappeared from radar.

The last hit plotted on the aircraft's flight data recorder showed the Q400 at 900' MSL, with the aircraft descending at 100 knots in a right bank, nose-down attitude. The accident site is approximately 650' MSL.

New revelations include that the plane's anti-icing systems -- including activation of the pneumatic boots on the Q400's wings and empennage -- were turned on shortly after takeoff from Newark, apparently in response to reports of possible icing along the route of flight.

Chealander said Monday crews are working to recover pieces of the wreckage. The NTSB hopes to finish up the on-scene investigation by Wednesday, at which time a snowstorm is expected to hit the region.

Despite that deadline, the NTSB did pause to allow some of the passengers' families to see the accident site for themselves Monday.

"We stood down, and allowed them an opportunity to go in there and pay their respects," Chealander said Monday. "That's all I'd like to say. That was a private time for them and I won't describe it any other way."

FMI: www.ntsb.gov