Continental TurboProp crash inbound for Buffalo
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Tailplane stall?
Although we have to wait for the findings of the investigation, it is already pretty clear that is was not a tailplane stall. All indications like stall warning, wing rocketing etc. are typical for wing stall. Further, with the flaps extended only to about 10°, a tailplane stall is very unlikely, apart from the fact that on this airplane tailplane stall very unlikely anyway (except maybe if we suspect total failure of tail de-icing system) . The only thing that hints toward tail stall is that it happened when the flaps were extended. However, that could be coincidence of circumstances. The wing stall could have happened for a very simple reason: low airspeed after level off and gear selection. Gear extension on this aircraft produces considerable drag and airspeed goes down fast in level flight if power is not increased. And the crew may have been distracted by noticing the ice. That of course is speculation at this point.
But, if it was a wing stall for any reason, the crew obviously thought it was a tailplane stall and they did the recovery procedure for that, like retracting flaps and pulling back on the yoke. By that they aggravated the situation until it was not recoverable, due to low altitude.
That may not explain why the got into this situaion in the first place, but it could explain why the recovery did not work.
But, if it was a wing stall for any reason, the crew obviously thought it was a tailplane stall and they did the recovery procedure for that, like retracting flaps and pulling back on the yoke. By that they aggravated the situation until it was not recoverable, due to low altitude.
That may not explain why the got into this situaion in the first place, but it could explain why the recovery did not work.
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I am repeating myself WW......
Inferior manually operated deicing system........Rubber boots (prone to wear and possibility of "bridging") as opposed to hot bleed air.
By its nature a TP spends more of its time at lower levels than its RJ counterpart and thus has more opportunity to pick up ice.
Inferior manually operated deicing system........Rubber boots (prone to wear and possibility of "bridging") as opposed to hot bleed air.
By its nature a TP spends more of its time at lower levels than its RJ counterpart and thus has more opportunity to pick up ice.
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did anyone PIREP severe icing?
there were no pireps of severe icing were there?
why?
whynot?
well, pilots might not see it, or they might be reluctant to use the term severe as it would pretty much make other pilots avoid that route.
SO...how much ice was there , really?
BUT beyon the ICE, I want to know why a pilot who knew that severe icing required the use of hand flying would have the plane on autopilot?
Was he tired, lazy, dumb?
Maybe the icing was not so bad, maybe the airspped indicator had problems, maybe this or that.
OR maybe he was so tired from a 22 hour day, he turned on the AP??????????
why?
whynot?
well, pilots might not see it, or they might be reluctant to use the term severe as it would pretty much make other pilots avoid that route.
SO...how much ice was there , really?
BUT beyon the ICE, I want to know why a pilot who knew that severe icing required the use of hand flying would have the plane on autopilot?
Was he tired, lazy, dumb?
Maybe the icing was not so bad, maybe the airspped indicator had problems, maybe this or that.
OR maybe he was so tired from a 22 hour day, he turned on the AP??????????
If you thought you had a tail plane stall but didn't, the stick pusher activation could be misidentified as part of the tail plane stall (stick being pulled forward with significant force.) You might then try and overpower the stick pusher in the belief that you were recovering from the tail plane stall.
Gender Faculty Specialist
AerocatS2A it's doubtful the stick shaker/pusher activated as the autopilot was still engaged when the aircraft crashed.
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i dont think the crew initiated a stall recovery procedure, when raising flaps and gear after the first signs of the stall.
i rather think they initiated a go around. "Flaps 10, Gear up!"
i rather think they initiated a go around. "Flaps 10, Gear up!"
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breezyDC
try to read my post again...think about my reference to being tired. I don't think the pilot was dumb...I think he might have been tired from terrible rest regulations.
some styles of writing require people to imagine in order to get the full concept.
in plain english, if there wasn't severe icing, what was wrong with being on autopilot?
I think we depend too much on automation and any amount of icing above trace should require hand flying
try to read my post again...think about my reference to being tired. I don't think the pilot was dumb...I think he might have been tired from terrible rest regulations.
some styles of writing require people to imagine in order to get the full concept.
in plain english, if there wasn't severe icing, what was wrong with being on autopilot?
I think we depend too much on automation and any amount of icing above trace should require hand flying
Originally Posted by Chesty Morgan
AerocatS2A it's doubtful the stick shaker/pusher activated as the autopilot was still engaged when the aircraft crashed.
Originally Posted by Noiffsorbutts
They Fly in it because they do not have any choice.
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AerocatS2A, I've just heard the report on Sky News and it doesn't really make it clear. I see where you're coming from so I retract what I said.
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Autopilot
According to Fox News, citing an NTSB member, the autopilot was still on when the plane crashed.
FOXNews.com - Flight 3407 Was on Autopilot When It Crashed - Local News | News Articles | National News | US News
FOXNews.com - Flight 3407 Was on Autopilot When It Crashed - Local News | News Articles | National News | US News
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Does this plane have autothrottles?
anyone out there know if the Q400 has autothrottles?
wasn't there an AD about static source or pitot tube icing on this plane in 2007?
wasn't there an AD about static source or pitot tube icing on this plane in 2007?
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D&T wrote:
Not at all, D&T....Great to share knowledge! 
I can't comment on your experience on the Q4 (as I have no experience on that derivative) but it's very unlikely on the 1/2/3. In my 12 years on the 1/2/3, not once in many "fail to inflate" events did a faulty boot cause the DEICE PRESS caution light to illuminate for me (even with a complete boot separation on one occasion). The only way we could tell in each instance was the advisory light did not illuminate, and a visual inspection confirmed the boot wasn't inflating. (I'd imagine that's the reason for having a separate QRH procedure for both DEICE PRESS and "Airframe boot advisory light fails to illuminate".
I could see your example happening if there were a significant leak in the pneumatic system, but the caution light would only illuminate during the period the Distributor Valve port was open on the "inflate" cycle on the faulty boot.
A single (or multiple) boot/s failing to inflate can also be caused by ice in the Distributor Valve assembly, meaning no de-ice air is actually getting to (what might be) a serviceable boot. The Dash is well known for this phenomenon (in Oz, anyway).
Aerocat, the reason I didn't mention the standby trim is because, as you correctly stated, it is only used in an abnormal situation.
WingoWango, yes the 1/2/3 uses a trim wheel on the centre pedestal when not in A/P.
P.S. to all the naysayers. I loved my time on the Dash. It was totally enjoyable to operate and I did fly it by "choice".
Sorry to pick you apart. The DE ICE caution DOES indicate when you fail to get inflation on a single boot. Certainly did to me last week anyhow. A single boot that doesn't reach correct pressure sets it off, and you isolate the sides to determine which boot it is. The fault is commensurate with the light above the LHS flickering or not coming on at all.
I can't comment on your experience on the Q4 (as I have no experience on that derivative) but it's very unlikely on the 1/2/3. In my 12 years on the 1/2/3, not once in many "fail to inflate" events did a faulty boot cause the DEICE PRESS caution light to illuminate for me (even with a complete boot separation on one occasion). The only way we could tell in each instance was the advisory light did not illuminate, and a visual inspection confirmed the boot wasn't inflating. (I'd imagine that's the reason for having a separate QRH procedure for both DEICE PRESS and "Airframe boot advisory light fails to illuminate".
I could see your example happening if there were a significant leak in the pneumatic system, but the caution light would only illuminate during the period the Distributor Valve port was open on the "inflate" cycle on the faulty boot.
A single (or multiple) boot/s failing to inflate can also be caused by ice in the Distributor Valve assembly, meaning no de-ice air is actually getting to (what might be) a serviceable boot. The Dash is well known for this phenomenon (in Oz, anyway).
Aerocat, the reason I didn't mention the standby trim is because, as you correctly stated, it is only used in an abnormal situation.
WingoWango, yes the 1/2/3 uses a trim wheel on the centre pedestal when not in A/P.P.S. to all the naysayers. I loved my time on the Dash. It was totally enjoyable to operate and I did fly it by "choice".
Last edited by Hugh Jarse; 16th Feb 2009 at 04:10. Reason: Becuz I caren't spel!
Driver, I don't have a lot of faith in a news organisation making the distinction between autopilot on at time of impact and autopilot on until just prior to impact when the same organisation has this link in their story:
Yeah I didn't really think you'd have forgotten all about it. Consider it an expansion for the sake of completeness rather than a correction.
On the subject of the DEICE PRESS caution. On the little Dashes that you and I flew/fly, the DEICE PRESS caution indicates de-ice pressure below 5.5 PSI and is sensed at the passenger door seal (which is supplied by de-ice pressure.) So you're right that there is no direct link between a failure of a boot and the DEICE PRESS caution on the little Dashes, but it seems the 400 doesn't have all that much in common with the little ones anyway.
Click here to read about prior trouble with the type of jet involved in the crash.
Originally Posted by Hugh Jarse
Aerocat, the reason I didn't mention the standby trim is because, as you correctly stated, it is only used in an abnormal situation.
On the subject of the DEICE PRESS caution. On the little Dashes that you and I flew/fly, the DEICE PRESS caution indicates de-ice pressure below 5.5 PSI and is sensed at the passenger door seal (which is supplied by de-ice pressure.) So you're right that there is no direct link between a failure of a boot and the DEICE PRESS caution on the little Dashes, but it seems the 400 doesn't have all that much in common with the little ones anyway.
Last edited by AerocatS2A; 15th Feb 2009 at 20:33.
