Hope To Complete On-Scene Investigation By Wednesday
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
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
"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."