Aspen, Colorado Canadair crash

[BlueMax]

New video of the crash from multiple angles

http://www.youtube.com/watch?v=KAorF4UfMpU

[3WE]

I agree with Evan that, unlike the FedEx crash, in this case the last strong pitch down after the last bounce doesn't look like the result of PIO. It doesn't seem the result of the pilot's intentional inputs. More like, with the last bounce (which was quite violent itself) the pilot slumped on the yoke or something in the plane got damaged, bent or something.

Keyword: "looks like"

Probably both come into play......

[Gabriel]

Probably both come into play......

Both what?

[Evan]

Would a much shorter and much lighter aircraft be able to pitch in a much more pronounced matter...

Be able to, yes, But does that look like textbook PIO to you? Would a bizjet dealing with controlled PIO inputs end up on its nose like that? That first bounce seems pretty severe. I wonder if there was structural failure to the elevators or stabilizers.

[Gabriel]

In other fora and aviation news media they are speculating that the plane might have stalled after the first bounce and that could be the cause of the pitch down.

After watching the videos several times I think that the pitch down was so violent and of such magnitude that the airplane might have stalled after all...

... in negative AoA and Gs!!!!

Stall: The airplane goes down and the nose follows.
"Active" pitch down: The nose goes down and the plane follows.
Make your own conclusion.

[3WE]

In other fora and aviation news media they are speculating that the plane might have stalled after the first bounce and that could be the cause of the pitch down.

After watching the videos several times I think that the pitch down was so violent and of such magnitude that the airplane might have stalled after all...

... in negative AoA and Gs!!!!

Stall: The airplane goes down and the nose follows.
"Active" pitch down: The nose goes down and the plane follows.
Make your own conclusion.

C'mon Gabriel...when the engine stalls, the plane violently pitches over!

However, it would also appear that he heroically steered away from the ramp so as to not harm innocent bystanders.

(No, actually I am with you and Evan that something was pushing the plane nose down- the appearance was that it was 'actively' and strongly pitching over and not 'passively' nor 'PIOey')

[guamainiac]

My question is how violent is the rebound of the strut compression and rebound in that aircraft.

I have only witnessed strut compression (porpoising) on an A-3 a long time ago down at RAAF Townsville. Three long bounces but fortunately our fellows were on a long military strip, a luxury not afforded by the Aspen runway.

[Gabriel]

I have only witnessed strut compression (porpoising) on an A-3 a long time ago down at RAAF Townsville. Three long bounces but fortunately our fellows were on a long military strip, a luxury not afforded by the Aspen runway.

I don't think that the outcome in this case would have been any different if at the moment of the last... eeeeerrrr... touchdown, they still had 15000 ft of runway remaining.

[3WE]

I don't think that the outcome in this case would have been any different if at the moment of the last... eeeeerrrr... touchdown, they still had 15000 ft of runway remaining.

Devil's advocate moment...

The crew might have been more willing to use the coal levers (emphasis on the word "might")

Cue up the comment to "wait for the final report"

[elaw]

My question is how violent is the rebound of the strut compression and rebound in that aircraft.

I have only witnessed strut compression (porpoising) on an A-3 a long time ago down at RAAF Townsville. Three long bounces but fortunately our fellows were on a long military strip, a luxury not afforded by the Aspen runway.

I don't think that the outcome in this case would have been any different if at the moment of the last... eeeeerrrr... touchdown, they still had 15000 ft of runway remaining.

Not to put words in anyone's mouth, but I wonder if what he meant was that due to the short runway length (in the pilots' perception) they were trying a little too hard to get it "down and stopped" quickly?

[Evan]

In other fora and aviation news media they are speculating that the plane might have stalled after the first bounce and that could be the cause of the pitch down.

Tail stall?

The a/c seems to be moving along quite nicely in terms of airspeed. Would a sudden upward vault from the bounce cause them to surpass critical angle on the tailplane? (I expect a long answer)

[3WE]

...Would a sudden upward vault from the bounce cause them to surpass critical angle on the tailplane? (I expect a long answer)

No.

[Gabriel]

Tail stall?

I don't think so.

The a/c seems to be moving along quite nicely in terms of airspeed. Would a sudden upward vault from the bounce cause them to surpass critical angle on the tailplane?

I don't think so.

(I expect a long answer)

I don't think so.

[Evan]

I don't think so.

I don't think so.

I don't think so.

So what kind of stall causes a pronounced pitch down like that rather than roll or flat descent? If stall did at altitude that I think it might solve the stall problem.

[3WE]

So what kind of stall causes a pronounced pitch down like that rather than roll or flat descent? If stall did at altitude that I think it might solve the stall problem.

No kind of stall...

Stall means significantly reduced "lift" from an airfoil.

What I say below is hard to put into words and contains subtleties.

After a stall, the aircraft actually responds a little bit gentle (the stalling 747 in the load shift crash noses over gracefully ). Because you "lose a chunk of lift", the plane is responding somewhat more passively. Contrast this with an aerobatic display where the plane can whip around much more crisply.

The STRONG pitch over we see in this crash suggests that a the tailplane surfaces were working very well and not in a stall condition.

I know it can seem violent when an unfriendly plane stalls (and ONE wing drops markedly)...but again, contrast that with the very crisp maneuvers that can come from a plane who's controls are working correctly.