Buffalo Q400 crash

On May 15, 7:37*am, Mike Ash wrote:
In article
,

*xyzzy wrote:
The way you recognize a tail stall is that pitch control becomes
abnormal when flaps are extended. *Plus knowing that you're in icing
conditions.

This still sounds like a total crapshoot to me. You can lose pitch
control during a regular stall, and icing can precipitate a regular
stall as well. Obviously in this case the signs were interpreted
incorrectly. Surely it's not a case of "heads we live, tails we die"?
There must be some way to tell which kind of stall is happening besides
these indications which clearly weren't correct in this case, isn't
there?

I guess there doesn't *have* to be, but it's kind of scary if there
isn't.

yes, another reason why it's best for guys like you and me to stay out
of icing conditions. You have to be pretty skilled and experienced
and know what you're doing, which is what we expect from ATP pilots.

As others have said, you can distinguish the difference if you really
know what you're doing, but better not to take that chance if you can
avoid it (which us PPL's, without the pressures of airline scheduling,
can do).

xyzzy wrote:
On May 13, 2:14 pm, Ron Garret wrote:
In article
,



bod43 wrote:
On 13 May, 12:57, Robert Moore wrote:
James Robinson wrote
The drop in airspeed was unnoticed, and the stall seemed
to catch them completely by surprise.
I wonder what the stall warning was doing all of this time?
Bob Moore
It appears that it was the stall warning (stick shaker) that the
captain (pilot flying) reacted to.
The reaction was to immediately pull back pretty hard
quickly precipitating an actual stall. 80% power was also
selected immediately. The stick was held back pretty much
until impact.
This boggles my mind. I'm just a PP but throughout my training I've had
it drilled in to me to lower the nose on an impending stall. How can
any pilot not know that, let alone one who is getting paid to fly
passengers?

It may boggle the mind of a PP like you (or me for that matter) who
seldom or never flies in icing conditions. However in icing
conditions a tail stall is possible, and the recovery from that is
exactly what this flight crew did. Yes, I know the Q400 is alleged
not to be suspectible to this but the captain had just come from a
type that is, and the FO spent a good part of the five minutes before
the crash chatting about how she feared icing, had never experienced
it before, and how would she handle it, etc. So then after chatting
and worrying about icing, they got something that felt/looked like it
could be an ice-induced tail stall and since it was on their minds
they did the recovery from that. They acted on instinct and it was
the wrong instinct. IMO.

Perhaps that is exactly what happened. But their indication was the
stick shaker (aircraft stall warning system), which only indicates wing
stalls, not tail stalls. Regardless of type, the only correct response
to the stick shaker/stick pusher was to perform normal (wing) stall
recovery. Instinct should lower the nose immediately when the stick
starts shaking.

"Jessica" wrote in message
...
xyzzy wrote:
On May 13, 2:14 pm, Ron Garret wrote:
In article
,



bod43 wrote:
On 13 May, 12:57, Robert Moore wrote:
James Robinson wrote
The drop in airspeed was unnoticed, and the stall seemed
to catch them completely by surprise.
I wonder what the stall warning was doing all of this time?
Bob Moore
It appears that it was the stall warning (stick shaker) that the
captain (pilot flying) reacted to.
The reaction was to immediately pull back pretty hard
quickly precipitating an actual stall. 80% power was also
selected immediately. The stick was held back pretty much
until impact.
This boggles my mind. I'm just a PP but throughout my training I've had
it drilled in to me to lower the nose on an impending stall. How can
any pilot not know that, let alone one who is getting paid to fly
passengers?

It may boggle the mind of a PP like you (or me for that matter) who
seldom or never flies in icing conditions. However in icing
conditions a tail stall is possible, and the recovery from that is
exactly what this flight crew did. Yes, I know the Q400 is alleged
not to be suspectible to this but the captain had just come from a
type that is, and the FO spent a good part of the five minutes before
the crash chatting about how she feared icing, had never experienced
it before, and how would she handle it, etc. So then after chatting
and worrying about icing, they got something that felt/looked like it
could be an ice-induced tail stall and since it was on their minds
they did the recovery from that. They acted on instinct and it was
the wrong instinct. IMO.

Perhaps that is exactly what happened. But their indication was the stick
shaker (aircraft stall warning system), which only indicates wing stalls,
not tail stalls. Regardless of type, the only correct response to the
stick shaker/stick pusher was to perform normal (wing) stall recovery.
Instinct should lower the nose immediately when the stick starts shaking.

Maybe. But, if the Q400 has a stick pusher, then it could really confuse
the issue--take a look at the FAA/NASA video on tailplane icing at
http://video.google.com/videoplay?do...23060735779946

Here is a link for considerable additional info, although it does appear to
include the FDR data which is linked elsewhere in this thread:
http://aircrewbuzz.com/2009/02/dash-...o-buffalo.html

We really don't know whether they actually had tailplane ice at the time,
not whether they did not, and we never will know because that sort of
evidence would not reasonably survive a crash.

Peter Dohm wrote:

We really don't know whether they actually had tailplane ice at the time,
not whether they did not, and we never will know because that sort of
evidence would not reasonably survive a crash.

Knowledgeable people (as eg. NTSB's accident investigators) tend to read
a lot out of the FDR data. I'm pretty sure we *will* know when the final
accident report is released.

"Peter Dohm" wrote:

We really don't know whether they actually had tailplane ice at the
time, not whether they did not, and we never will know because that
sort of evidence would not reasonably survive a crash.

The manufacturer testified at the NTSB hearings that their certification
tests showed that the aircraft wasn't subject to tailplane stalls.