Colgan 3407 Down in Buffalo

[ksu_aviator]

The gear is probably sturdier, more dense and they hit at 31 degrees nose down.

The data all points to a sudden pitch up resulting in a stall and probably a spin. The question is why?

 

[belchfire]

I could only see one of the main gear. My suspicion is that the one in the picture was sheared away from the wreckage and fire damaged areas by contact with the house, hence no dirt or debris on it.

 

[TOOL CRIB]

I thought the gear was on the way back up when they hit?

 

[172driver]

AP on, power back, configuring, slowing, anticipating GS intercept. GS doesn't capture or hasn't yet, deck angle rising, crew realizes they're getting slow, adds power but does not disengage AP and lower nose, stall, spin?

I hope there's more to the story.

 

[Singlecoil]

I wonder if the icing simply served to divert their attention the way it has all of us.
Power levers at idle, aircraft slowing and being configured on speed. Autopilot keeps rolling the trim back to maintain altitude as the aircraft slows until stick shaker. Stick shaker occurs, full power is applied, autopilot kicks off, nose rises steeply as the trim is all the way back with full power, stall occurs, stick pusher shoves the nose down hard.

There have been several instances when I have been the non-flying pilot and thought the autopilot was off because the flying pilot had his hands completely on the controls and was allowing his hands to be moved by them. I could see the FO in this case not being aware the autopilot was on as well.

 

[MALSR]

This article says they had 134kt calibrated airspeed before the gear was lowered. That's pretty darn slow considering they were at flaps 5.


http://www.flightglobal.com/article...-3407-pitched-up-despite-anti-stall-push.html

 

[rchcfi]

I too am wondering why it would pitch up first.

I think there is more to the story than just "ice brought them down"

also, see these pics, if they landed bottom first (for lack of a better term), why is the gear so pristine?

I believe they landed inverted, flat, facing the other direction

http://www.cnn.com/2009/US/02/15/buffalo.plane.crash/index.html#cnnSTCPhoto

I was thinking the same thing about the MLG in the photos, but then why is the tail in such perfect condition?

 

[satpak77]

I was thinking the same thing about the MLG in the photos, but then why is the tail in such perfect condition?

I don't know, I have the same question

 

[goodgig]

This article says they had 134kt calibrated airspeed before the gear was lowered. That's pretty darn slow considering they were at flaps 5.


http://www.flightglobal.com/article...-3407-pitched-up-despite-anti-stall-push.html

What would be considered a nominal speed in this config?

 

[belchfire]

What would be considered a nominal speed in this config?

Don't know...seems okay to me based on my experience in other types but I don't know the Q-400.

I have ridden on many of the Dash 8 variants. I did my time as a turboprop guy and never flew any of the RJ's...but I feel better when I walk up to a Dash than when I walk up to a CRJ or ERJ. Fracking thing is built like a tank and they look right.

 

[LowlyPropCapt]

What would be considered a nominal speed in this config?

I don't know about a Q400, but in a -100/200/300 that is way slower than when you would normally drop the gear... The gear horn goes off at 130 Kts so long as the power levers aren't at takeoff. Still a ways off from stall, mind you, but it is slower than normal.

 

[Flyin2low]

I don't know where the power levers where before the event occurred, but I can imagine that they where at a point that set them up for the appropriate approach speed.

BINGO

 

[ksu_aviator]

I've thought about the scenarios above that state that the power lever position is the only factor that caused the accident and I just don't see how that would work. From what I've seen in the NTSB briefings, the power application followed the rapid pitch and was nearly simultaneous to the stick shaker.

I'm not rated on the Q400, I've never even set foot on one, but every other aircraft I've flown we've trained for that exact scenario and the aircraft never had a violent pitch up to the point of stall and then entered a spin before the pilot could correct just because the power went from idle to full.

I'm not saying that it is impossible, it just doesn't seem probable. And I'm stuck on this idea that they entered the spin because of the slow speed at which they impacted the ground even though the aircraft had a steep nose down pitch and full power and a very high descent rate.

I've been throwing around some ideas:

Sudden weight shift in the cargo area?
Catastrophic failure of the elevator controls?
Extremely fast trim runaway (highly improbable)?
Some weird reaction to the ice?

What can cause the Q400 to pitch up so rapidly that it enters a stall?

 

[WSurf]

I've thought about the scenarios above that state that the power lever position is the only factor that caused the accident and I just don't see how that would work. From what I've seen in the NTSB briefings, the power application followed the rapid pitch and was nearly simultaneous to the stick shaker.

I'm not rated on the Q400, I've never even set foot on one, but every other aircraft I've flown we've trained for that exact scenario and the aircraft never had a violent pitch up to the point of stall and then entered a spin before the pilot could correct just because the power went from idle to full.

I'm not saying that it is impossible, it just doesn't seem probable. And I'm stuck on this idea that they entered the spin because of the slow speed at which they impacted the ground even though the aircraft had a steep nose down pitch and full power and a very high descent rate.

I've been throwing around some ideas:

Sudden weight shift in the cargo area?
Catastrophic failure of the elevator controls?
Extremely fast trim runaway (highly improbable)?
Some weird reaction to the ice?

What can cause the Q400 to pitch up so rapidly that it enters a stall?

Not sure if this has been talked about, but the Dash 8 is known at times to have the Trim Freeze up. It hasn't happen to me, but I have had a few Captain's talking about being in some really good icing conditions and having the Trim Freeze up.

Just thought I would throw that out there. Like I said it has never happened to me personally. Maybe some that experienced it can chime in.

 

[Publishers]

There was some questions related to when the stick shaker went off, auto pilot knocked off, and we had the nose down turn, what would the pilot have done? Did he rapidly pull back at that point somehow leading to the flat type spin that seems to be the way it went in.
Another thing is the switch that increases airspeed in ice and the 134. Is this right or should it have been more by the 20 knots mentioned. I thought the briefer did an excellent job of not putting the crew out there while explaining what is going on. While the media does not get it right, the people they get there by this point are usually the more educated aviation press while initially you have people just trying to fill some air..