MIT UAV soaring technique

At 21:40 06 December 2010, shkdriver wrote:

Anyone have any experience/thoughts to share about winch launching a
shempp-hirth SHK? My example has CG tost hook on gear leg.

Thanks,
Scott W.

Scott,

I had a 17m SHK many years ago. The difference between minimum and maximum
all up weight was about 20 lbs which made one very careful about spinning.
I never had problems launching behind a car, but a very experienced pilot
at Lasham spun his in from a wire launch.

Are you fully experienced on winch launching? A modern high power winch is
rather different to the F100 trucks we used to use for launching, and I
would say that the SHK could bite a little more than some gliders if you
are too sudden with your pull up or if you pull too hard. A V tail is not
the same as a normal T tail, and I imagine that turbulent air off the wing
at a high angle of attack could possibly cause issues.

I enjoyed the glider very much, but you need to be very careful rigging
the main pin (if you are not aware of this then please do research the
issue, it is on the internet - we had a fatality in the UK this year I
believe because of mis-rigging with this system which is very easy to do)
and watch the CofG and spin characteristics. It will bite if you deviate
too far from best practice on winch launching. The BGA has published very
good notes on winching.

If you already have experience with the SHK and / or you are a higher
hours pilot, then it is fine so long as you treat it with a little more
respect than, for example, a K6e.


Mike

On Dec 6, 2:40*pm, shkdriver
wrote:
Anyone have any experience/thoughts to share about winch launching a
shempp-hirth SHK? My example has CG tost hook on gear leg.

Thanks,
Scott W.

--
shkdriver

A caution not specific to the SHK but it may apply. For the first
winch launch in any new glider type pay particular attention to seat
back and rudder pedal adjustment. There should be no possibility that
you will slip backward during the launch.

I learned this one the hard way. I had quite a few hours in the Std
Jantar, all aero tow. On my first winch launch I slid backward so my
feet were not in contact with the pedals. I continued the launch with
my elbows frantically clawing for grip on the cockpit side walls but
was able to remain in control. Every other glider I had winched had a
more upright seating position so I had never seen this problem before.

Andy

On Wed, 08 Dec 2010 06:20:37 -0800, Andy wrote:

A caution not specific to the SHK but it may apply. For the first
winch launch in any new glider type pay particular attention to seat
back and rudder pedal adjustment. There should be no possibility that
you will slip backward during the launch.

I've heard this said about the Discus 1 as well, but though I've winched
them quite a bit I've not experienced it myself so it must only apply to
pilots who prefer a seating position that's different from mine. I can
imagine that with the seat fairly well forward the straps would be pretty
much horizontal behind your shoulders and so won't to a lot to stop you
sliding up the back of the seat.

Bottom line: Making quite sure your straps are tight is even more
important for winch than aero-tow due to the higher initial acceleration
and much steeper climb-out.


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

On Dec 8, 3:57*am, Michael Clarke
wrote:
At 21:40 06 December 2010, shkdriver wrote:



Anyone have any experience/thoughts to share about winch launching a
shempp-hirth SHK? My example has CG tost hook on gear leg.

Thanks,
Scott W.

Scott,

I had a 17m SHK many years ago. The difference between minimum and maximum
all up weight was about 20 lbs which made one very careful about spinning..
I never had problems launching behind a car, but a very experienced pilot
at Lasham spun his in from a wire launch.

Are you fully experienced on winch launching? A modern high power winch is
rather different to the F100 trucks we used to use for launching, and I
would say that the SHK could bite a little more than some gliders if you
are too sudden with your pull up or if you pull too hard. A V tail is not
the same as a normal T tail, and I imagine that turbulent air off the wing
at a high angle of attack could possibly cause issues.

I enjoyed the glider very much, but you need to be very careful rigging
the main pin (if you are not aware of this then please do research the
issue, it is on the internet - we had a fatality in the UK this year I
believe because of mis-rigging with this system which is very easy to do)
and watch the CofG and spin characteristics. It will bite if you deviate
too far from best practice on winch launching. The BGA has published very
good notes on winching.

If you already have experience with the SHK and / or you are a higher
hours pilot, then it is fine so long as you treat it with a little more
respect than, for example, a K6e.

Mike

Good advice. There was an SHK winch fatal many years ago (Scotland?),
where the pins were not fully home. The winch at Scott's club is not
overly powerful, nor is it wimpy for a small block V-8. I've driven
it. We had a phone chat a couple of evenings ago. Although it's been
29 years since I last winched in SHK S/N 1, I think I was able to
provide the normal cautions and caveats. Sure was fun to soar 5 hours
from a 50p ($1) launch;^) Scott's done his homework and actually did
quite a few winch launches during his training in both the trainer and
a light single seater, which is atypical for most US pilots. He's
also driven the winch a fair amount. He doesn't have many hours in
the SHK yet and is not in a big rush to jump on the winch with it.
The club didn't use the winch much during the past year, but has
committed to using it much more in the next, so he's looking forward
to winching the Sh*t Hot Kite (Schempp-Hirth Kirchheim manager's
description, not mine).

Frank Whiteley

On Dec 8, 2:20*pm, Andy wrote:
On Dec 6, 2:40*pm, shkdriver
wrote:

Anyone have any experience/thoughts to share about winch launching a
shempp-hirth SHK? My example has CG tost hook on gear leg.

Thanks,
Scott W.

--
shkdriver

A caution not specific to the SHK but it may apply. * *For the first
winch launch in any new glider type pay particular attention to seat
back and rudder pedal adjustment. *There should be no possibility that
you will slip backward during the launch.

I learned this one the hard way. *I had quite a few hours in the Std
Jantar, all aero tow. *On my first winch launch I slid backward so my
feet were not in contact with the pedals. *I continued the launch with
my elbows frantically clawing for grip on the cockpit side walls but
was able to remain in control. *Every other glider I had winched had a
more upright seating position so I had never seen this problem before.

Andy

Same thing happened to me in a DG101 a few years ago. Did a whole
winch launch keeping the stick just off the backstop with my
fingertips and with my feet nowhere near the rudder pedals. Always do
your straps up really tight for a winch launch, and if possible set
the rudder pedals a bit closer than normal. Only use firm cushions
behind you.

Derek C