Nimbus 4DT accident 31 July 2000 in Spain.

On Thu, 23 Jun 2005 21:27:25 UTC, Don Johnstone
wrote:

Now here's a question. Given the answer above why when
the wing drops at the start of a take off run (winch
or aero-tow) does everyone almost without exception
try and lift the downgoing wing with aileron?

Define "drops". How do you keep your wings level on the takeoff run?

Ian
--

I'll bite Ian

I suspect that keeping the wing off the ground with aileron in the
initial part of the ground run works because with the tailwheel/ skid
on the deck the effects of adverse yaw & secondary effect roll are
negated.

There is no way on Gods earth that the rudder of the Nimbus is going to
accelerate a dropping wing at the beginning of the ground run.
Personally I thing the rudder of the
Nimbus is there because us pilot types wouldnt but an hairyplane
without one

Ian

OK. For the wing drop I take the recovery action for
that. Spinning is more than stalling with the wing
down or indeed with wing drop. A spin involves the
aircraft autorotating with yaw, roll and pitch movement.
I suppose you could say that if there significant yaw
present then that needs to be stopped. I think the
important point is that the angle of attack needs to
be reduced. If that can be achieved by use of the elevator
then that is all that is required.
I am not sure that I can explain satisfactorily in
words, but I could definitely demonstrate the difference.

At 22:24 23 June 2005, Ian Johnston wrote:
On Thu, 23 Jun 2005 21:27:25 UTC, Don Johnstone
wrote:

The answer is again simple and goes to recognition.
A stall with wing drop is just that and provided action
is taken to solve that problem, unstall the wing,
the
a spin will be prevented. A spin is the result of
failure
at the first step for whatever reason. Everyone properly
trained will know the difference.

OK, so how would you described the difference. How
far does the wing
have to drop before /you/ use spin recovery rather
than stall
recovery? I'm genuinely interested: it's not supposed
to be a trick
question in any way.

Ian

On Thu, 23 Jun 2005 16:34:41 -0500, Bob Johnson
wrote:

Has anyone mentioned the yaw string on these wide birds? What's it doing
during incipient diving vs. spinning?

During lots of spin training flights (that include spiral dives to
show the difference) I *never* looked at the yaw string. Even in a big
bird the diffrence between a dive and a stall/spin is easy to detect
(and recover) if you have a little experience in this glider and
halfways correct spin training.

Frankly spoken, pulling the stick back hard enough to break off the
wings shows that the pilot was lacking the most basic skills to fly
that bird.


Bye
Andreas

On 23 Jun 2005 21:27:25 GMT, Don Johnstone
wrote:


Now here's a question. Given the answer above why when
the wing drops at the start of a take off run (winch
or aero-tow) does everyone almost without exception
try and lift the downgoing wing with aileron?

.... because it works in 99 percent of the cases?


Bye
Andreas

At 02:06 24 June 2005, Andreas Maurer wrote:
On Thu, 23 Jun 2005 16:34:41 -0500, Bob Johnson
wrote:

Frankly spoken, pulling the stick back hard enough
to break off the
wings shows that the pilot was lacking the most basic
skills to fly
that bird.


well, possibly, but having got to the position where
you could either go through Vd or pull back what would
YOU do?

Bob Johnson:
pulling the stick back hard enough to break the wings
shows pilot .. lacking .. skills to fly that bird.

Robert William wrote:
having got to the position where you could either go
through Vd or pull back what would YOU do?

Is, 'Not getting into that position', an allowed response?

Jon.

Ian Johnston wrote:

In real life, on the final turn, you have approximately 0.3 seconds to
answer this question ...

I've always wondered about those "final turn spins". Yes, I know they
happen. I'm wondering nonetheless. It has been hammered in my heat right
from day one to watch that approach speed and to stay coordinated on
approach. Tolerance on the slow side: None. We won't let a student solo
before we are absolutely, positively sure he can and will acomplish
this. And when he gets his license, this will have become second nature
to him (just as not pulling back in a spin).

I'm not a great pilot and I'm making mistakes all the time. I can think
of a lot of ways how I could loose my life in a glider. But I'm
absolutely, positively sure that stalling/spinning in the final turn
will *not* be one of them.

Stefan

Ian Johnston wrote:

In real life, on the final turn, you have approximately 0.3 seconds to
answer this question ...

I've always wondered about those "final turn spins". Yes, I know they
happen. I'm wondering nonetheless. It has been hammered into my head
right from day one to watch that approach speed and to stay coordinated
on approach. Tolerance on the slow side: None. We won't let a student
solo before we are absolutely, positively sure he can and will acomplish
this. And when he gets his license, this will have become second nature
to him (just as not pulling back in a spin).

I'm not a great pilot and I'm making mistakes all the time. I can think
of a lot of ways how I could loose my life in a glider. But I'm
absolutely, positively sure that stalling/spinning in the final turn
will *not* be one of them.

Stefan

Don Johnstone writes
The answer is again simple and goes to recognition.

I think that was the point of the BGA's question

A stall with wing drop is just that and provided action is taken to
solve that problem, unstall the wing, the a spin will be prevented. A
spin is the result of failure at the first step for whatever reason.
Everyone properly trained will know the difference.

I know the theoretical and practical difference between a spin and a
stall with or without a wing drop, and understand the difference in
recovery for each. However,

The BGA Instructor's Course question asked:
"The offical recovery from a stall with wing drop is different from
the official recovery from a spin. At what point do you, personally,
transition from one to the other?"

At what point do you NOT put the stick forward to reduce AoA and
alleviate the stall and instead centre the controls then kick a boot
full of opposite rudder in to stop the spin? Assuming no flaps, that
is...

Or is the question, and the suggestion that you transit from one
recovery procedure through to the other at some definite point in time,
intrinsically wrong? Should it be, "What is the difference between a
stall with wing drop and a fully developed spin?"

I have thought about this and decided that if I ever get to the point
where I do get to a fully developed spin at final turn height I am
going to spin in, rather that than tent peg half way through the
recovery.

Presumably working on the grounds that impacting at the lower, stable
velocity of a spin is going to hurt less than doing so at the higher,
increasing velocity of the initial part of the recovering dive? I can
appreciate the sense in that argument, though personally I doubt I could
accept the inevitability of the impact without putting up a struggle and
trying to recover despite the futility of the situation.

My philosophy teaches recognition of the approach of the problem so it
can be prevented and this is still not given sufficient emphasis in
training.

It was in mine. Repeatedly hammered into me through graphic description
and demonstration by a number of different instructors throughout the
period of my training.

Yes train people to recover from fully developed spins but if you do
the job right and train so that they recognise the approach and take
the correct preventative action they will never need to recover from a
spin.

Though that overlooks the other essential advantage of spin training. It
teaches familiarity and confidence with the aircraft in unusual and
discomforting attitudes, which, IMHO, makes you far less likely to panic
and make a potentially bad situation terminally worse if you ever find
yourself there, whether through fault of your own or otherwise.

Besides which, as one of my favourite instructors was once quoted as
saying when asked why he had spun on a certain occasion; "Well, it's
just about one of the most exiting things you can do in a glider".

That is, of course, unless the glider concerned is a Fox


--
Bill Gribble
http://www.scapegoatsanon.demon.co.uk
- Learn from the mistakes of others.
- You won't live long enough to make all of them yourself.