Further Thoughts on Continental Connect Flight 3407
Travel Blog • Rob Verger • 04.07.09 | 3:16 PM ET
It’s been nearly two months since Continental Connect Flight 3407 crashed in Clarence Center, New York, while on its approach to Buffalo-Niagara International Airport. Over at Ask the Pilot, Patrick Smith analyzes the most recent news, which he describes as “fascinating and disturbing.” While initially ice had been a prime suspect, Smith writes, “Investigators are focused instead on what appears to be an egregious case of pilot error.”
Smith walks the reader through the plane’s final moments: “For reasons unknown it was flying slightly slower than it should have been. This, together with the effects of at least mild icing, caused activation of the so-called stick shaker—a warning system that vibrates the pilots’ control columns in advance of an aerodynamic stall.”
He continues: “The basic steps to stall recovery are lowering the nose, leveling the wings, and increasing power. That’s Flying 101. Instead, the captain allegedly pulled back on the control column, raising the nose and throwing the airplane into a full aerodynamic stall from which, at an altitude of less than 2,000 feet, recovery was impossible.”
The NTSB has published this update. Fifty people died in the accident.
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Rob Verger is a frequent contributor to World Hum and the site's former air travel blogger. His articles and photographs have appeared in the Boston Globe and other publications, and he's a former undergraduate writing instructor at Columbia University. If you like, .(JavaScript must be enabled to view this email address) or follow him on Twitter.
James Tidwell 04.08.09 | 2:30 AM ET
The reason for pulling back on the yoke would have been due to a tail stall due to ice buildup on the horizontal stabilizer. As the NTSB report states, the aircraft basically went out of control post flap extension, which is a good indication of a tail stall, not a wing stall. This stall occurs when the horizontal stabilizer, also an airfoil, exceeds its critical angle of attack, and has completely different and most opposite recovery procedures than a typical wing stall. So, being as a tail stall was the likely cause of this, the captain made the correct reaction. However, indications are he over corrected, and therefore forced the aircraft into a wing stall at that point, and with the ice buildup on the wings, the aircraft would have probably stalled at a much lesser pitch attitude than typical. Always a shame when an airliner crashes, but as pilots we usually always learn something from it.
Tired of hearing Tail Stall 04.08.09 | 8:14 PM ET
Tail stall has been said by many people with exprtise to not be a realistic explanation of the Flight 3407 tragedy.
For one thing, the DAsh 8 Q400’s design is not succeptible to tail stall.
For another thing, a tail stall would have initially pushed the nose suddenly downward, but the NTSB has reported that’s not what happened.
Also, tail stalls reportedly won’t activate the stick shaker on the Q400.
The more likely explanation is a wing stall after the nose pitched so far upward.
Rob 04.09.09 | 10:34 PM ET
Thanks so much for the thoughtful comments here. Patrick Smith has just written a follow-up to his original column—which I quoted from above—in which he looks at the possibility of a tail stall: http://www.salon.com/tech/col/smith/2009/04/10/askthepilot316/index.html The pertinent discussion is at the end of the piece, at the bottom of page two.
Tired of hearing Tail Stall 04.10.09 | 4:49 PM ET
Thanks for the alert about Patrick Smith’s column.
He hypothesizes a more believable way how the concept of tail stall might have been involved - not an actual stall, but that the 3407 pilot might have made a mistaken fast diagnosis of a tail stall.
However, there’s reasons to doubt even that possibility. As one of the Salon comment writers pointed out in response to Smith’s column, the Dash 8 Q400 has been publicly said to in fact be not be succeptible to tail stall. Presumably the pilot would be told that during traning for that aircraft. Also, the commenter noted the pilot’s response actions didn’t include all that would have been done for a tail stall. And he very probably would have bene trained to realize the stick shaker activation indicates an impending wing stall, not a tail stall.
Perhaps eventually the fully released transcript of the cockpit voice recorder might indicate whether in the heat of the moment the pilot thought a tail stall was happening, or something else.
Tired of hearing Tail Stall 04.10.09 | 4:57 PM ET
To clarify my comment a few minutes ago:
The following Salon comment suggests “Maybe there haven’t been any Q400 accidents/incidents attributable to tail icing because the Q400 IS NOT susceptible to this condition. This was made clear by both the NTSB and Bombardier in the aftermath of the Buffalo crash”
http://letters.salon.com/tech/col/smith/2009/04/10/askthepilot316/permalink/24bc2e1e29e452b092f9516973597de6.html
The other point that the pilot’s actions didn’t include all that would’ve been the proper response to a tail stall (if that’s what he quickly thought was happening) were actually in the column itself, rather than in a comment as I had implied.