Nimbus 4DT accident 31 July 2000 in Spain.

Your point doesn't hold. If during the winch launch failure exercise the
instructor has to take the controls and/or overrule the student's input, the
student won't go solo and he will have this game played over and over again.

If an instructor doesn't feel comfortable to train winch failure on a proper
winch launch at *any* height, he shouldn't be instructing winch launches.

--
Bert Willing

ASW20 "TW"


"Ian Johnston" a écrit dans le message de news:
dzZo7CxomoOm-pn2-Pk4JoJw3pd71@localhost...
On Thu, 30 Jun 2005 12:41:44 UTC, Stefan
wrote:

Ian Johnston wrote:

the student/ to recover safely..." There are some places and heights
where the decision about where to go after the Big Bang hs to be made
very quickly, and right first time. And if the student gets it wrong

Then the instructor gives him exactly two tenths of a second to do the
right thing. Otherwise the instructor takes over and the student can try
again at the next launch.

And that is my point: a practice winch launch failure isn't like a
real one, because ultimately you know that you won't be allowed to do
anything really stupid.

Ian

Stan Hall presented his analysis of the Nimbus-4DB accident in Minden,
NV, 1999. Stan's analysis is scary, to say the least.

The article, Probing for the Smoking Gun, was reprinted in the Soaring
Association of Canada's free flight, 2/04. Go to the link below. Click
on free flight on the side bar. Go to free flight back issues - 2004 -
issue 2. Down load the PDF file.

http://www.sac.ca/

Bill Feldbaumer 09

Hi,

Ah, but do they have the confidence and ability to recover safely from
a failed attempt to recover safely from an attempt at any stage?

I believe they do or I would not want to get in the glider with any
of the lot :-).

I am not even ready to fly solo so who am I to judge, though? One interesting
bit of information I gleaned is that some instructors keep a hand on the
brake handle. Just in case a student makes the decision to land NOW and pops
the brakes before making the aircraft fly properly.

I am not aware of any problems or even accidents caused by this mode of
training. I believe it is standard procedure in germany and not an invention
by our instructors.

Ciao, MM
--
Marian Aldenhövel, Rosenhain 23, 53123 Bonn. +49 228 624013.
http://www.marian-aldenhoevel.de
"What did you expect to see out of a Torquay hotel bedroom window? Sydney
Opera House perhaps? The Hanging Gardens of Babylon? Herds of wildebeest
sweeping majestically across the prairie!" Basil Fawlty

Hi,

And that is my point: a practice winch launch failure isn't like a
real one, because ultimately you know that you won't be allowed to do
anything really stupid.

That is true of every critical phase of flight while in training.

I firmly believe that my instructor is going to save himself. There are
situations where he can let mistakes evolve and the student face the
consequences before fixing the problem and times where he can't.

My instructors so far have let me try to fix my mistakes on my own wherever
safely possible. I have cried for help a few times at the start BEFORE they
did, though :-).

Trust in the instructor has no effect on the reality of the failure. If the
student takes right and prompt action he has proven he would have survived
at this occasion and hopefully will react the same the next time. If he
doesn't take the right action he can be sure there are many more such
exercises in his future before he has any chance to try it without someone
watching from the back seat.

Also there is not much to be learned from NOT taking the right action. I am
sure I could talk an instructor into simulating it at altitude but all I
could find out is that there is no safe alternative to the procedure we train
for. And possibly have some fun doing so, I admit.

Ciao, MM

PS.: I have read somewhere that flight instructors do not teach anyone how to
fly. They just keep students alive while they learn on their own. This
very accurately reflects my current experience.
--
Marian Aldenhövel, Rosenhain 23, 53123 Bonn. +49 228 624013.
http://www.marian-aldenhoevel.de
"What did you expect to see out of a Torquay hotel bedroom window? Sydney
Opera House perhaps? The Hanging Gardens of Babylon? Herds of wildebeest
sweeping majestically across the prairie!" Basil Fawlty

If Stans analysis is right, and I can see no obvious
flaw, once the spiral dive/spin situation is met then
the chances of a sucessful recovery are slim. The 4DT
would not be unique in this. Perhaps a tail parachute
is an essential item of equipment.

Food for thought


At 15:18 30 June 2005, Bill wrote:

Stan Hall presented his analysis of the Nimbus-4DB
accident in Minden,
NV, 1999. Stan's analysis is scary, to say the least.

The article, Probing for the Smoking Gun, was reprinted
in the Soaring
Association of Canada's free flight, 2/04. Go to the
link below. Click
on free flight on the side bar. Go to free flight back
issues - 2004 -
issue 2. Down load the PDF file.

http://www.sac.ca/

Bill Feldbaumer 09

The article was very interesting. The idea of aileron
stiffness at high bending was thought-provoking.

'Abandoning ailerons for a more effective way of starting
and stopping roll...' Perhaps a reference to
full span spoilers for roll?

'the smoking gun was the aircraft's incredibly high
performance.' This is consistent with, but not a proof
of, the things I've written before about USA fatalities
and L/D.
Of course, this was however NOT a ridge flying accident.

The article didn't mention the possibility that the
other
pilot may have popped the airbrakes/two pilots on the
controls working at odds with each other. Of course
there
is absolutely no way to confirm or deny this.

Lastly, I liked the article's end, and the idea of
big bold red letters in the AFM. It also occered to
me that some of the
'seconds to accelerate from stall speed to ...' and
a lot
of the ideas we have, and how we practice spins and
spirals, is in STILL AIR. I generally don't go up
in huge
thermals/turbulence to practice spins, specifically
so I don't exceed Va and gust loads and 1/3 deflection,
etc.

Does a spin turn into a spiral on it's own sometimes
in turbulent air? Can AOAs be changed by turbulence
alone,
with no movement of controls? Oh, yes.

Start throwing in severe turbulence (which we love,
when it
suits us) and I think we are closer to the 'naked edge
of safety'
than is obvious.

The 2-32 accident in Hawaii was anectdotally in 'the
toilet bowl' there in turbulent air, too. Shear 10/20/30
knots in a few
seconds and 1/4 mile vertically or horizontally, and
our
still air analysis can't be done with a pristine slide-rule...
At 17:12 30 June 2005, Don Johnstone wrote:
If Stans analysis is right, and I can see no obvious
flaw, once the spiral dive/spin situation is met then
the chances of a sucessful recovery are slim. The 4DT
would not be unique in this. Perhaps a tail parachute
is an essential item of equipment.

Food for thought


At 15:18 30 June 2005, Bill wrote:

Stan Hall presented his analysis of the Nimbus-4DB
accident in Minden,
NV, 1999. Stan's analysis is scary, to say the least.

The article, Probing for the Smoking Gun, was reprinted
in the Soaring
Association of Canada's free flight, 2/04. Go to the
link below. Click
on free flight on the side bar. Go to free flight back
issues - 2004 -
issue 2. Down load the PDF file.

http://www.sac.ca/

Bill Feldbaumer 09






Mark J. Boyd

Deploy the "Other Spoilers"?
As a pilot of an 18m Ventus, I don't think my high-speed-dive-recovery
problems are nearly as bad as those of a pilot of a 25m Nimbus, but
nevertheless, these problems still feel uncomfortably close to home.
In light of the well-discussed problems of deploying spoilers to control
airspeed while trying to pull out of a steep dive, how about dropping the
landing gear?
On the Ventus, the main wheel swings forward as it is lowered, so I can
imagine that at airspeeds approaching or exceeding Vne, it might not be
possible to get the gear down-and-locked, but could even a partially
deployed wheel and the open wheel bay add enough drag to correct an
otherwise unrecoverable situation?
Even more radically, how about jettisoning the canopy as a speed control
measure?
Or both?
What do the experts on this newsgroup think?

"Don Johnstone" wrote in
message ...
If Stans analysis is right, and I can see no obvious
flaw, once the spiral dive/spin situation is met then
the chances of a sucessful recovery are slim. The 4DT
would not be unique in this. Perhaps a tail parachute
is an essential item of equipment.

Food for thought


At 15:18 30 June 2005, Bill wrote:

Stan Hall presented his analysis of the Nimbus-4DB
accident in Minden,
NV, 1999. Stan's analysis is scary, to say the least.

The article, Probing for the Smoking Gun, was reprinted
in the Soaring
Association of Canada's free flight, 2/04. Go to the
link below. Click
on free flight on the side bar. Go to free flight back
issues - 2004 -
issue 2. Down load the PDF file.

http://www.sac.ca/

Bill Feldbaumer 09

On Thu, 30 Jun 2005 13:04:56 UTC, Stefan
wrote:

Ian Johnston wrote:

And that is my point: a practice winch launch failure isn't like a
real one, because ultimately you know that you won't be allowed to do
anything really stupid.

Your solution then for a more realistic training?

None. It's as good as it gets. I'm just pointing out a necessary
limitation.

Ian

There are certain points during an air tow, where there are also very small
margins for error. I also believe that winch launches have major risk
advantages over air tow, particularly due to the elimination of the tow
plane from the risk equation.

Unfortunately, the field I fly out of is too short for winch launching to be
practical.

Mike Schumann

"Stefan" wrote in message
...
Bill Daniels wrote:

I am fighting a lonely battle to convince my fellow USA pilots that winch
launch is a perfectly normal way to launch gliders and not some invention
of
the devil.

Just three things to consider:

A which launch brings you to a certain altitude above the site. At some
places, this gives you enough options to find a thermal, at other sites,
it does not.

A winch operation doesn't mix well with other traffic. It's doable, if
everybody is willing.

And, most important: If done correctly, a winch launch is safe. But there
is an extremely small margin for errors. I love winch launches, but they
are dead serious, literally.

Stefan

From what I have seen, I doubt that winch launches require more people than
air tow. One of the biggest problems we have with air tow is finding tow
pilots who have the necessary hours in type to meet insurance requirements.
I suspect that it would be much easier for your typical club to train and
line up qualified winch operators than finding tow pilots.

Mike Schumann

"T o d d P a t t i s t" wrote in message
...
Mike I Green wrote:

It is too bad that so many influential pilots in the US have been
knocking winch towing for such a long time.

I've been flying since the early '70's and I've met a lot of
glider pilots. I can't really think of any influential
pilots who have been knocking winch launching. I know of
many who've experienced it in Europe and think it would be
a great way to decrease the cost of launching, but something
always prevents it. That "something" may be lack of
experience with winches in the U.S., lack of available
winches or the cost of a good one, the difficulty of mixing
with non-glider traffic, etc.

As far as I can see, the successful U.S. winch operations
seem to mostly be clubs who own/control their own field and
have sufficient available labor to support winch launches or
clubs on large open airports (former WWII airfields etc.)
where there's plenty of space. Those favorable conditions
just aren't that common. When you add concerns about
startup expense and lack of familiarity of U.S. pilots, you
can understand why winch launching is hard to get started
here.

T o d d P a t t i s t - "WH" Ventus C
(Remove DONTSPAMME from address to email reply.)