Practice Violated Company Policy For Icing Conditions
A National Transportation Safety
Board official confirmed Sunday that downed Continental Express
flight 3407 was being flown on autopilot in apparent icing
conditions up to the final moments preceding
the crash.
In conjunction with FAA recommendations, NTSB spokesman Steve
Chealander said Colgan Air, the plane's operator, recommends that
pilots manually fly during all icing conditions... and
requires them to do so when there's evidence of severe icing.
"You may be able in a manual mode to sense something sooner than
the autopilot can sense it," Chealander told the Associated Press,
emphasizing the need to hand-fly the airplane to better feel how
it's really flying when conditions are critical.
An autopilot will trim out an aircraft, within its capabilities,
to compensate for changing conditions -- including airflow
disturbances caused by icing -- without the flight crew necessarily
becoming aware of any abnormalities. Preliminary information
retrieved from the flight data recorder indicates the aircraft was
on autopilot until the aircraft's stick pusher activated, in order
to keep the plane from stalling.
Other information about the crash also suggests the plane may
have stalled, even going into a flat spin prior to impact. Popular
conjecture that icing was a major factor in the crash would seem to
support the theory, but at this point is still speculation.
As ANN reported, the Bombardier Dash 8-Q400
twin-engine turboprop airplane went down at approximately 10:15 pm
(EST) Thursday, February 12, crashing into a house during an
instrument approach to Buffalo International Airport (BUF).
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.
All aboard the aircraft -- 44 passengers, two pilots, two flight
attendants, and one off-duty pilot -- lost their lives. There was
one ground fatality, a person inside the home impacted by the
plane.
ANN will continue to provide updates on the NTSB investigation
into the crash of flight 3407 as information is released.