Glider Aerobatic Workshop, Williams California

We are planning a Glider Aerobatics Workshop at Williams Gliderport!
Target date is Sunday, February 21.
Plan on 8:30 start with 1.5 hour of video and introduction to glider
aerobatics and judging.
Followed with dual flights in ASK-21.
Participants pay for aircraft time (0.3hr), tow (4,000 to 5,000), and
instructor time while flying.
While people are flying, those on the ground get to be aerobatic
judges.
After flying we will get together to review the day and see if there
is interest in another event.
Hope to be all done by 2:00pm.

This is for a basic introduction to aerobatics. In the ASK-21 we are
talking about speed control, up-lines, down-lines, loops, rolls, and
inverted flight. The ASK-21 does not spin.

For more information contact:
Guy Acheson

The "-21 "does not spin"????

I must have been hallucinating in the dozens I have done in them. You
might want to read the exhaustive and definitive USAF Test Pilot
School Report on the subject as well - written after someone at the
USAF Academy spun one into the ground.

wrote:
The "-21 "does not spin"????

I must have been hallucinating in the dozens I have done in them. You
might want to read the exhaustive and definitive USAF Test Pilot
School Report on the subject as well - written after someone at the
USAF Academy spun one into the ground.

The ASK21 does spin when the CofG ist aft of 400mm. But any halfways
normally grown pilot will put the CofG too much forward.

Since 1982 there has been TM #4 which describes a modification which
allows fit lead ballast to the tail and put the CofG in the spinning
range. For many years, only the USA and Switzerland had accepted this
TM, so the Germans and others had to resort to other gliders to train
spinning, which was pretty absurd given the aerobatic capabilities of
the ASK21. Only recently that TM became valid for the rest of Europe,
too. (I don't know about the rest of the world.)

On Sun, 20 Dec 2009 12:37:15 +0100, John Smith wrote:


The ASK21 does spin when the CofG ist aft of 400mm. But any halfways
normally grown pilot will put the CofG too much forward.

That is just an urban myth.

I've spun ours two up with normal CG position. No tail collar, no fancy
rear weights, nothing added. I was in front (70kg) and the instructor
weighed a little more, 80kg maybe. The instructor showed me the technique
and then I spun it a couple of times to make sure I could do it too.

Granted it doesn't spin easily, but it can be spun in normal trim with
two pilots of medium weight or less. Spinning it is much easier than
provoking a right-hand spin from a G.103A


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Martin Gregorie wrote:
That is just an urban myth.

I've spun ours two up with normal CG position.

The manual is often misunderstood in this point. It states that with a
CofG of less than 315mm (=12.4 in) the ASK21 wold not spin at all under
any circumstance. With a CofG more aft it *may* be possible to make it
spin, however this depends a lot on the total mass, the mass
distribution and the spin entry technique, which can be tricky. (Exact
speed, nose not too high or too low, help with ailerons...) This can be
achieved without tail ballast. But only with a CofG aft of 400mm
(=15.75in) the spin can be reliably provoked with the standard method
and the resulting spins are reliably sustained, and this CofG cannot be
achieved without tail ballast. Hence the tail ballast for training.

The already mentioned report by the USAF (AFFTC-TR-89-27) states the same.

So with a CofG between 315 and 400 mm you are not "safe" of spins, but
the ASK is not suited for basic spin training either.

On Dec 19, 12:11*pm, Guy wrote:
We are planning a Glider Aerobatics Workshop at Williams Gliderport!
Target date is Sunday, February 21.
Plan on 8:30 start with 1.5 hour of video and introduction to glider
aerobatics and judging.


What a great class! Sure would like to see one on the east ( or
north ) coast !

Make sure you invite the media - this would be a positive attention
getter for your operation and Soaring in general.

On Sun, 20 Dec 2009 15:48:58 +0100, John Smith wrote:

but the ASK is not suited for basic spin training either.

I'd agree that its probably too hard to spin for spin training. Doing
spin training in a very spin-resistant glider or needing to add a tail
weight both can give the wrong impression to a student. However, that's
not the same as saying it won't spin without a tail weight. As I said,
I've done it and AFAIK that particular glider hadn't had any rear end
damage that would have moved the CG back. We don't own any tail weights:
why would we when we have a Puchacz?

Similar suitability remarks apply to the G.103A. We used to have an
instructor who could reliably spin it left but not right but he no longer
instructs. I'm told that the G.103C (Acro III if you prefer) spins well
in both directions but I haven't tried since our club doesn't have one.

The only real answer is to have a trainer that does spin well or access
to one.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Martin Gregorie wrote:

I'd agree that its probably too hard to spin for spin training.

And that is exactly what this thread has been all about:

We are planning a Glider Aerobatics Workshop at Williams Gliderport!
....
This is for a basic introduction to aerobatics.

BTW, I did my primary aerobatics training in an ASK21 with tail ballast.
It spins wonderfully, and it was a very good exercise to calculate the
tail ballast, mount it and then having to believe my own calculation.

Ok Boys and GIrls,
Good response to the proposed glider aerobatics workshop.
For those who care, we are working on adjusting the CG on the ASK-21s
to facilitate spinning.
The workshop will be Sunday, February 21. We plan to start at 8:30.
Williams has motels. Williams has some good places to eat. Two
towplanes are available so you could spend Saturday practicing to
impress your friends on Sunday.
If you would like to attend, please let me know via this forum. As we
get closer to the date, and as people commit, I will post options for
meals and such.
I know there are a bunch of acro junkies and acro wannabees out
there. Here is a welcoming place to satisfy those desires.

Guy Acheson
SZD-59 "59"

If you would like to attend, please let me know via this forum.

Are there any prerequisites? Or, to phrase it differently, would a
freshly minted private pilot (who happens to enjoy spinning and would
love to learn how to fly loops) benefit from attending the workshop?

Bart