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Old June 22nd 05, 05:52 PM
M B
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I'm not as interested in spins and spirals. This is
important, but covered adequately already on RAS and
elsewhere.

To me, I'm more interested in the less commonly discussed
human factors. Specifically what factors contribute
to accidents?

Both Eric and Bert's posts made me think about some
things
along with what Stefan and Casey wrote.

In my experience, I have seen and been a part of confusion
in
the cockpit. One pilot is saying one thing and the
other is
contradicting it. I've also had both pilots on the
controls at the same time, with opposite pressures
applied.

I've seen and felt myself during critical moments both
a
narrowing of perceptions and a loss of sense of time.
Seconds seem like hours and vice versa. In aerobatic
training,
the focus was not on control inputs, but correctly
applying
the RATE of control changes.

I've also noted that I use trim extensively when flying,
and this
reduces the feedback I get about airspeed from the
stiffness of
the elevator controls. Casey wrote about how trim
(and maybe flaps) change the behavior of a spin, and
require different control pressures. Flaps, water,
a second passenger, trim,
quite a different 'feel' depending on these factors.


Bert mentioned that training in fully developed spins
in one of these ships might be (ahem) hard to find.
And what ships are similar to these which ARE certified
for full spin training?

If I put all these observations into this accident,
the
post-accident debrief reads as a bit of fiction, none
of
which is in either of the real accident reports:

*****fictional report begins****

We were tight in a thermal, with my dad at the controls.
It was bumpy, and the vario was turned up loud and
beeping.
I was scanning for traffic over my shoulder, and my
dad
was telling a story. When I looked forward, we were
nose down.
I said 'I got it' and took the controls. I was trying
to pull back but something was stopping the stick,
so I paused
for a second. My dad said 'it's spinning!' again and
again very loud.
I think he may have been trying to push forward while
I was pulling.
Between the vario, his yelling, and me thinking about
the flap lever,
I don't remember hearing any airspeed indications.

I glanced at the wrap-around ASI, and couldn't tell
if we were stalling or
going through 140kts. I wasn't the one who'd done
the trim, so
I couldn't tell if the pressures were light on the
elevator or
if that was just trim. I was distracted by my Dad's
yelling.

It had been a while since I had done full spin training.
I flew with
the test pilot when I got the glider, but he didn't
demonstrate
any full spins or spiral dives with recovery. I did
some
wing drops, but nothing like a full spiral or spin
like this.

I think my dad finally let go of the stick, and when
he did
it came back. I thought I did it slowly, but I might
have done it faster than I should have, because there
was a loud
snap and then the glider was rotating violently. I
popped
off the canopy and parachuted out.

*******fictional report ends*****

From this made up sequence of events, if I were getting
training
for such a glider, I'd want to focus on

1. positive exchange of controls, with the control
change echoed back
2. CRM agreement that whoever is on the stick handles
the emergency
(assuming both are fairly similarly qualified pilots).
3. reduction of distractions (radio, vario volume,
wrap-around ASI)
4. training in a glider certified for full spins that
is as alike
the glider I want to fly as possible.
5. enough acro and unusual attitude training to control
my rate of
control inputs during recovery, without panic.

Is this fictional report what actually happened? Probably
not,
but it is a fusion of my own experiences and what I
have read in
various fatal accident reports in various aircraft.

I don't believe just going up and doing some spin/spiral
recovery
training is specific enough. CRM issues and distractions
have
happened enough to fully 'trained' and 'experienced'
airline
and aerobatic pilots that I think human factors are
as important as
time on the stick feeling the pressures and hearing
the wind.

All right, kids, flame away! For the rest, if you
have specific
constructive insights that are on topic, I'd like to
hear them.
Thank you to Bert and Eric and Stefan for your useful
discussions.

As far as my wrap-around ASI confusion theory goes,
I can't ell if it is a good one or not. Clearly these
pilots
either didn't accurately know their airspeed, or they
DID, and just
misapplied corrective action. There is a subtle
difference there...

At 04:48 22 June 2005, Kilo Charlie wrote:

'Eric Greenwell' wrote in message
...
M B wrote:


Don't the controls feel differently at 30 knots and
100 knots? That should
be a good clue as you begin the spin recovery.


--
Change 'netto' to 'net' to email me directly

Eric Greenwell
Washington State


I am a partner in a Nimbus 3D. I have not had a lot
of time in it but have
flown aircraft of all kinds for 36 years including
hundreds of glider and
powered aerobatic hours. In order to get the Nimbus
to go beyond the green
arc it takes a very large amount of forward stick even
with the trim all the
way to the forward stop.....with flaps in -2. I absolutely
disagree that it
would be easy to let it get away from you and end up
in a spiral with the
exception of possibly entering it from a spin. The
spin enty on the other
hand is docile and easy to recover from. As has been
pointed out, if one is
clueless re incipient spins then the scenario in these
2 accidents might
easily unfold. Only education, planning and practice
will prevent similar
accidents.

Casey Lenox
KC
Phoenix



Mark J. Boyd