Re: accelerated stalls

[Hugh Haskell <hhaskell@MINDSPRING.COM>]

At 1:49 -0500 11/1/01, John S. Denker wrote:

> At 11:54 PM 10/31/01 -0500, Hugh Haskell wrote:
> > If you are going to slow for the angle of bank, the airplane can stall.
> > Fun to do at altitude, but really scary if it happens as you turn onto
> > your final approach during landing when you are only a couple of hundred
> > feet up.
> >
> > I'm sure John D. can tell you of at least one instance where a student did
>  >it to him.
>
> Don't be so sure.  In thousands of landings, I've never been anywhere close
> to the situation described.  And I plan to keep it that way.
>
> > Probably only one, though, since that is a lesson that you learn very well
> > the first time-if you survive.
>
> Flight training does _not_ depend on learning from barely-survivable
> incidents.  Flight training depends on using safe methods to teach you how
> to stay away (well away) from any barely-survivable situations.

You misinterpret me, John. I made no assertions about how flying is
learned, only that low altitude accelerated turn stalls are easy for
beginning students to get into. I have never had one happen to me,
either, but then I'm not a CFI. But many of my friends are, and I
have heard many of them tell stories of how, early in their
instructing career, they let their attention wander at a critical
moment and the student got into such a stall or nearly did, and only
their quick recovery averted disaster. And the new CFI learned not to
let attention off the leash, for even a moment, especially when close
to the ground.

My reference was not to a lesson learned by a student-I fully agree
with your statement about how flight training does not depend on
getting out of harrowing experiences. But you cannot deny that such
escapes should be and often are, educational. AOPA Pilot has carried
articles about such events and what the victim learned from them. The
articles were originally titled "I learned about flying from that"
but seem to have morphed more recently into "Never Again."
> > I'm sure that was the kind of stall that little girl who was trying to
> > solo across the country a couple of years ago, when she spun in soon after
> > takeoff from Cheyenne, Wyo.
>
> Don't be so sure.  Available records suggest there was a stall, but not a
> spin (as alleged above) or even an accelerated stall (as alleged farther
> above).
>
>    http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001208X05676&key=1
>    http://www.avweb.com/sponsors/ntsbrepo/dubroff.html

Thanks for the references. I'll check them out. I based my comments
on newspaper articles, and my experience flying out of Cheyenne,
where the ground rises gently as you leave the northbound runway, and
it can get a bit tense if you can't maintain a rate of climb that
exceeds the rate at which the ground rises beneath you. I had read
that the plane was overloaded, and it was, iirc, summer, and
therefore hot, and it looked to me from my distant vantage point that
she (or her instructor) tried to turn back to the airport and did it
too quickly, leading to an accelerated turn stall. Since my analysis
is purely an armchair one, it certainly could be wrong.

> Furthermore, there was no little girl flying "solo".  There were three
> people on board.  There was one and only one pilot on board.  The pilot
> wasn't a little girl.  As pilot in command, he was directly responsible
> for, and the
> final authority as to, the operation of that aircraft.

I am fully aware of this. The PIC, however, was not an "experienced"
pilot, having been a CFI for a relatively limited time (less than a
year, as I recall), according to the news reports, and with not a
whole lot of hours under his belt. Of course, he bears the
responsibility for the safety of the flight, as the PIC, but there
were lots of other factors involved. My candidate for the main
culprit in this accident is the girl's mother, who, according to the
news reports I read, was the stem-winder of this whole operation.
Apparently the girls instructor was under considerable pressure to
get this flight over with so they could start cashing in on the
girl's accomplishment. This situation seems to be one that was an
accident waiting to happen-a young, possibly impressionable CFI, with
only limited experience, and possibly also caught up in the hype, and
a classic "stage mother" type back home pushing everybody to get on
with it. If it hadn't happened at Cheyenne, it would have probably
happened somewhere else. I suspect the fact that, had he taken over
the controls at some point in this process the whole effort at the
record would have been voided, had an impact on the instructor's
apparent delay in taking over to prevent the accident. Inexperience
(combined with the desire to be a participant in the girl's
accomplishment) doesn't relieve him of his responsibility, but it can
go at least part way to explain why he did (or didn't do) what he did
(or didn't do).

> Media hype about the little girl has no legal or practical
> significance.  The pilot made a series of outrageously bad decisions --
> well beyond the bounds of ordinary reasonable judgement and beyond the
> bounds of the regulations several times over.

Absolutely, but see above.

>  >Turning when you are low, slow and heavy can get you into really big
> > trouble very fast, especially if you are inexperienced.
>
> This is an unhelpful mixture of ideas.
>   -- Being outside the certified weight&balance envelope is a bad
> idea.

True. And clearly the responsibility of the instructor. I would hope
that he would have required his student to complete the proper
calculations, and then would check her work. I don't think the
general public is aware of just how restricted the payload of these
little planes is-usually around 20% of the maximum takeoff weight, or
less. And that factor is reduced even more when the take-off location
is at high altitude and the temperature is high, both factors in the
Cheyenne situation. It had probably been true for the entire
flight-you have two adults plus the child, and all the luggage they
might need for a two-three week jaunt, and it isn't hard to imagine
that the people plus their baggage would amount to more than the
plane ought to be carrying on a day like it was in Cheyenne that day.

>  Being inexperienced is no excuse, and being experienced is no
> justification.

My inexperience remark was meant to refer to the instructor. See
above. And there is never an excuse for an experienced pilot to make
these mistakes. They are things that are to be taken care of on the
ground.

>   -- Failure to maintain safe altitude is a really bad idea.  There's no
> excuse for this, either.
>   -- Failure to maintain a safe airspeed is also a really bad idea,
> although what's safe and what's not depends somewhat on altitude and other
> factors.
>   -- Et cetera.

As I pointed out above, it would appear that at least part of the
blame for their lack of maintaining a safe altitude has to do with
the geography around Cheyenne airport, also air temp and aircraft
weight, which adversely affect climb rates (but all of which should
have been within the purview of the instructor). It is not uncommon,
when faced with a "low and slow" situation, to try to gain altitude
by pulling up the nose, which, as you know, usually has just the
opposite effect.

> Please don't go telling stories about all the horrible things that can
> happen in airplanes -- you're scaring my customers away.

If someone decides not to learn to fly because they are worried of
the possible consequences, it is probably for the best. I have a
little plaque hanging on my wall that shows a picture of a WWI era
airplane stuck in a tree in a field where there are apparently no
other trees within sight. The text accompanying the picture reads
"Aviation in itself is not inherently dangerous. But to an even
greater degree than the sea, it is terribly unforgiving of any
carelessness, incapacity or neglect." That is no less true today than
it was when Wilbur and Orville were the scourge of the skies. Anyone
who isn't acutely aware of this has no business at the controls of an
airplane.

> There are in fact
> three envelopes:
>    1) The actual limits of safety.
>    2) The stuff we do with advanced students, by informed consent of all
> concerned, under controlled conditions, which explores SOME of the limits
> of what the airplane can do.  This is very far within the aforementioned
> safety limits;  for instance, it might involve stalling the airplane at
> 3000 feet when we know it takes 50 feet to get it unstalled if everything
> goes right and 200 feet if everything goes wrong, leaving at least 2800
> feet to spare.
>    3) The stuff we do with passengers, and with beginning students, which
> is a tiny subset of what the airplane (and the properly-trained pilot) can
> handle.

All three of which were clearly exceeded by that little girl's instructor.

Hugh
--

Hugh Haskell
<mailto://haskell@ncssm.edu>
<mailto://hhaskell@mindspring.com>

(919) 467-7610

Let's face it. People use a Mac because they want to, Windows because they
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