Colgan 3407 Down in Buffalo

[twighead]

I remember watching this video in training at Piedmont. Not sure if it was during new hire training or during a CQ.

They haven't played it at any of the 4 that I've been to.

 

[Captzaahlie]

They haven't played it at any of the 4 that I've been to.

I'd watch it before my next flight then.....

 

[Captzaahlie]

It sucks to know that everything from that video the Q400 does in non-icing conditions, such as elevator buffet and major pitch-down during flap movement from 15 to 35. If it does that when clean you can only imagine would it would do in bad icing conditions.

NOTE WHAT IS SAID AT 31 MINUTES AND ZERO SECONDS.......

http://video.google.com/videoplay?docid=3493859021331008391&hl=en

 

[HoserASA]

Investigator: Plane fell flat onto Buffalo house

By JOHN CURRAN, Associated Press Writer John Curran, Associated Press Writer – 13 mins ago

CLARENCE, N.Y. – A commuter plane that smashed into a house was pointed away from the airport it was trying to reach, investigators said Saturday, noting that it apparently fell flat.
Flight data showed the plane's safety systems warned the pilot that the aircraft was perilously close to losing lift and plummeting from the sky. The ensuing crash killed 49 people on the plane and one in the house.
Continental Connection Flight 3407 didn't nose-dive into the house, as initially reported by some witnesses, said Steve Chealander, a National Transportation Safety Board member.
The Newark, N.J.,-to-Buffalo flight was cleared to land on a runway pointing to the southwest, but it crashed with its nose pointed northeast, Chealander said. It will take as many as four days to remove human remains from the site, which he called an "excavation."
"Keep in mind, there's an airplane that fell on top of a house, and they're now intermingled," he said.
The plane — on its descent to Buffalo Niagara International Airport in a light snow and mist — plunged suddenly about six miles shy of the runway and exploded.
A "stick shaker" and "stick pusher" mechanism had activated to warn Capt. Marvin Renslow that the plane was about to lose aerodynamic lift, a condition called a stall that means there's not enough air under the wings to keep the plane elevated.
When the "stick pusher" engaged, it would have pointed the nose of the plane toward the ground to try to keep air under the wings, the last moments before it stalled and plunged to the ground.
Crash investigators picked through incinerated wreckage Saturday, gathering evidence to determine what brought down the plane. Icing on the aircraft is suspected to have played a role, but officials have stopped short of calling that the cause.
Experts were analyzing data from the black boxes, including statements by crew members about a buildup of ice on the wings and windshield of the plane, Chealander said.
Other aircraft in the area Thursday night told air traffic controllers they also experienced icing around the time that the plane went down.
Icing is one of several elements being examined by investigators, Chealander said, adding that a full report will probably take a year.
DNA and dental records will be used to identify the bodies, he said.
One aspect of the investigation will focus on the crew, how they were trained and whether they had enough time to rest between flights. Other investigators focused on the weather, the mechanics of the plane and whether the engine, wings and various mechanics of the plane operated as they were designed to.
Initial visual inspection of the engines indicates they were working properly, Chealander said.

Hoser
Roll Tide!

 

[Captzaahlie]

is it completely impossible that a sudden pitch down, vertical descent, down thru the bottom and a pull-out (if you will) and then crash (but now inverted) would could have caused the above orientation? To get it 180 degrees from the original heading is definitely a new twist to this case

I wonder if the wreckage will display clues as to being inverted or not at impact?

It's not impossible at all.....

NOTE WHAT IS SAID AT 31 MINUTES AND ZERO SECONDS.......

http://video.google.com/videoplay?do...31008391&hl=en

 

[Brody1]

Just want to make sure I got this right. To counteract a stall of the tailplane, one has to pull back on the yoke (according to the video). Now, the NTSB is saying that the stick shaker and STICK PUSHER activated shortly before impact. Seems to me there's a flaw in the design. Why would anyone want to have to fight a stick pusher during a tailplane stall, when the proper reaction is to pull back?

 

[Andy Neill]

Just want to make sure I got this right. To counteract a stall of the tailplane, one has to pull back on the yoke (according to the video). Now, the NTSB is saying that the stick shaker and STICK PUSHER activated shortly before impact. Seems to me there's a flaw in the design. Why would anyone want to have to fight a stick pusher during a tailplane stall, when the proper reaction is to pull back?

You want to keep it in the flying envelope. If the airspeed is too high it will tail stall. If the speed is too low it will main wing stall. Although the initial actions might include power to idle and nose up, you would want to add power and level after the tail stall is exited.

 

[WSurf]

You want to keep it in the flying envelope. If the airspeed is too high it will tail stall. If the speed is too low it will main wing stall. Although the initial actions might include power to idle and nose up, you would want to add power and level after the tail stall is exited.

Easier said then done, when in a stressful situation we revert to what was last learned. How many of us learned to recover from tail stalls?
Many would mistake this for a wing stall and use that recovery.

Bottom line is that this crew was in a almost no win situation at that altitude.

 

[Captzaahlie]

Just want to make sure I got this right. To counteract a stall of the tailplane, one has to pull back on the yoke (according to the video). Now, the NTSB is saying that the stick shaker and STICK PUSHER activated shortly before impact. Seems to me there's a flaw in the design. Why would anyone want to have to fight a stick pusher during a tailplane stall, when the proper reaction is to pull back?

I'm no where near being able to remotely call myself an aerospace engineer.........but here's my 2 cents...a common everyday stall is the norm
(therefore that's what you try to protect against, you can overpower a stick pusher). A tailplane only stall is a function of the a/c being redesigned by mother nature due to ice.... I wouldn't know how you could mechanically differentiate or detect between the two....
(and would it be cost effective for something so rare? I'm not being insensitive to the price of a human life, just saying that flight has some inherent risks involved....) that is why computers cannot fly a/c under all conditions. You obviously need a human mind calculating the best decision for a given event.​

 

[dmspilot00]

Why would the stick shaker activate if it was a tail stall, unless it was actually a wing stall? Or is it possible to have both at the same time?

 

[The Prussian]

My sense of all of this is that this aircraft...similar to what happened post Roselawn incident, is going to be relegated to flying the southern-tier states until they get these issues ironed out.

 

[ackattacker]

I'm no where near being able to remotely call myself an aerospace engineer.........but here's my 2 cents...a common everyday stall is the norm
(therefore that's what you try to protect against, you can overpower a stick pusher). A tailplane only stall is a function of the a/c being redesigned by mother nature due to ice.... I wouldn't know how you could mechanically differentiate or detect between the two....
(and would it be cost effective for something so rare? I'm not being insensitive to the price of a human life, just saying that flight has some inherent risks involved....) that is why computers cannot fly a/c under all conditions. You obviously need a human mind calculating the best decision for a given event.​

Tail stall occurs when the angle of attack goes excessively negative.

Main wing stall occurs when the angle of attack goes excessively positive.

The pusher only fires at high angles of attack. The pusher should not fire during a tail stall... however if a tail stall leads to an upset it is understandable at some point during the attempted recovery the angle of attack could exceed the amount required to fire the pusher.

 

[clr4theapch]

Of course we dont know the second by second time frame of things that happened.. but I would think it is actually possible to get a stick shaker/pusher if the crew responded to the tail stall by puling back on the yoke (as is the procedure for tail stalls) Then assuming that the tail started flying again, at the point it's possible that the AOT was now nose high enough and the airspeed was dropping low enough to activate the shacker/pusher..for a full wing stall...of course all of this could have happend in a matter of seconds..

So I see where this could happen.. God bless them.

 

[Brody1]

I'm no aeronautical engineer either, and maybe I'm being ignorant here, but it would appear that the design of a stick pusher/shaker doesn't allow it to tell the difference betweent the two. I haven't had the pleasure of fighting the stick pusher (yet), so I have no idea how difficult it would be to fight in actual flying conditions- especially if it's made worse by icing. It may not have mattered in this case- but what if it did?

Andy, I hear what you're saying, but what are the parameters of the flying envelope when the a/c is covered with ice? Like Wsurf said, our first reaction is usually the one we practice the most. Unfortunately, and assuming the info in the video is correct, that reaction can be catastrophic, espcially at low altitudes. Regardless of whether this was a contributing factor in the crash the other night, it would seem to me that any flight training department (and the FAA) should look very closely at this.

 

[LowlyPropCapt]

Tail stall occurs when the angle of attack goes excessively negative.

Main wing stall occurs when the angle of attack goes excessively positive.

The pusher only fires at high angles of attack. The pusher should not fire during a tail stall... however if a tail stall leads to an upset it is understandable at some point during the attempted recovery the angle of attack could exceed the amount required to fire the pusher.

I am not so sure about this...

I agree that the stick shaker/pusher activates at and beyond the wing's critical (excessively positive) AOA. But here is the thing... Increased airspeed aggrevates the stalled condtion in the case of a tailplane stall, since it causes the AOA to become more "negative." Since the nose would have been headed downhill during a tailplane stall event, at what point would the critical AOA of the wing have been exceeded? Furthermore, the pusher is inhibited below a certain altitude I am sure (Q pilots help me here?) The aircraft was already at 1500ft AGL... How much time would they have had to have a tailplane stall event, then get the airplane excessively slow so that the stick shaker and pusher activated prior to impact? Maybe if the airplane rolled over... I suppose a high LF could induce a high enough AOA, maybe.

I guess I am just spit ballin' here, but obviously something is missing. I don't think I would have expected a stick pusher activation with a tailplane stall event...

I am really curious to see what the rest of you think.

 

[AV1ATRX]

It's not impossible at all.....

NOTE WHAT IS SAID AT 31 MINUTES AND ZERO SECONDS.......

http://video.google.com/videoplay?do...31008391&hl=en

I'm on dial-up. What does it say?

 

[bailout]

I am not so sure about this...

I agree that the stick shaker/pusher activates at and beyond the wing's critical (excessively positive) AOA. But here is the thing... Increased airspeed aggrevates the stalled condtion in the case of a tailplane stall, since it causes the AOA to become more "negative." Since the nose would have been headed downhill during a tailplane stall event, at what point would the critical AOA of the wing have been exceeded? Furthermore, the pusher is inhibited below a certain altitude I am sure (Q pilots help me here?) The aircraft was already at 1500ft AGL... How much time would they have had to have a tailplane stall event, then get the airplane excessively slow so that the stick shaker and pusher activated prior to impact? Maybe if the airplane rolled over... I suppose a high LF could induce a high enough AOA, maybe.

I guess I am just spit ballin' here, but obviously something is missing. I don't think I would have expected a stick pusher activation with a tailplane stall event...

I am really curious to see what the rest of you think.

The time lines should tell. They did say there were major pitch changes up and down, so..

My thinking, is you get the tail stall, the nose drops, auto disconnect, then the pilots pull agressively backwards on the yoke, the aircraft pitches up radically, stick shaker/pusher goes off, dropping nose again, pilot pulls back, you still have the tail stall going on but now too slow, wing over stall, plane either rolls over, or flat 'spins', or rolls one way or the other, and hits the ground flat.

 

[airplane wizard]

Why would the stick shaker activate if it was a tail stall, unless it was actually a wing stall? Or is it possible to have both at the same time?

Maybe they stalled the wing when they pitched up to recover from the tail stall.

 

[ackattacker]

I am not so sure about this...

I agree that the stick shaker/pusher activates at and beyond the wing's critical (excessively positive) AOA. But here is the thing... Increased airspeed aggrevates the stalled condtion in the case of a tailplane stall, since it causes the AOA to become more "negative." Since the nose would have been headed downhill during a tailplane stall event, at what point would the critical AOA of the wing have been exceeded? Furthermore, the pusher is inhibited below a certain altitude I am sure (Q pilots help me here?) The aircraft was already at 1500ft AGL... How much time would they have had to have a tailplane stall event, then get the airplane excessively slow so that the stick shaker and pusher activated prior to impact? Maybe if the airplane rolled over... I suppose a high LF could induce a high enough AOA, maybe.

I guess I am just spit ballin' here, but obviously something is missing. I don't think I would have expected a stick pusher activation with a tailplane stall event...

I am really curious to see what the rest of you think.

I don't know about the pusher on a Q-400, but on the ATR the pusher is not tied in with the radio altimeter and is never inhibited in flight except for 10 seconds after takeoff.

Also, low speed is not a prerequisite for a main-wing stall. Only high angle of attack. Large excursion in pitch can cause a stall at any speed.

 

[Raskal]

Maybe they stalled the wing when they pitched up to recover from the tail stall.

The AOA had to go beyond positive limits to get a pusher-it won't go otherwise, to get there with flaps would have required a considerable change in angle. A recovery from a tailplane stall involves not only back pressure on the yoke but flaps being retracted, everything I've been taught says back pressure alone won't be enough.

To get a pusher means something else or a major upset in attitude...I don't think we'll know for a while.