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  • Continental Connection Flight 3407: The Icing Question
    Posted by Christopher Fotos 3:00 PM on Feb 16, 2009

    Most of the latest news reports on the NTSB's investigation appear to be a detailed recounting of the exact maneuvers as the Colgan Air flight crew lost control of their Bombardier Dash 8 Q400, as recounted here by the Buffalo News. There also continues to be a lot of discussion about icing and whether the pilots were in any way culpable for using autopilot in the face of an ice buildup.

    In a Buffalo News story titled Too Early To Tell If Icing Caused Crash, NTSB says, NTSB board member Steve Chealander says:

    When there is "severe" icing, the manufacturer of the airplane recommends that the autopilot be disengaged so the pilot can correct for weather conditions more efficiently, Chealander said.

    The NTSB also recommends that in icing conditions "you might want to disengage the autopilot so you have a manual feel for what might be changing because of the ice," he said.

    "We suggest you take it off autopilot to better feel the airplane and stay ahead of changes as a result of icing." However, he also said that the NTSB encourages pilots to "use autopilot to help you handle the workload in these highly intense weather situations. To say they shouldn't have been flying on autopilot is not correct."

    In this AP story at Washingtonpost.com, Chealander is quoted as saying the pilot may have rejected federal safety recommendations and the airline's own policy for flying in icy conditions by leaving the autopilot on even after he notified air traffic control that the flight crew had spotted ice on the leading edge of the wings and the windshield.

    The NTSB (and Chealander in some of the pressers I've seen) has emphasized it isn't clear that "severe" icing was present--the flight crew's discussion of "significant" icing doesn't really define how bad it was.

    And in that same AP story, discussing the sequence of events after the autopilot disengaged, Chealander also says it's possible the pilot over-reacted by pulling the nose up when the automatic anti-stall sequence would have pushed the nose down (which increases airspeed to overcome the stall).

    But, honestly, at this stage of the investigation they're far from knowing exactly what happened. In this blog posting at the Buffalo News Jerry Zremski calls Flight 3407 "The Preventable Tragedy," taking the lead from comments by former NTSB Chairman Jim Hall--but most commenters rap Zremski for jumping to conclusions.

    Below is a CBS video from Saturday about icing.  

    Incidentally, today is a federal holiday in the U.S., and also for the U.S.-based team of AvWeek, so postings (and stories posted to our homepage news section) will probably be lighter. I see that some of our journalists outside the U.S. are blogging away.

    Tags: tw99, icing, 3407, crash

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