New winch height record

"bagmaker" schrieb im Newsbeitrag
...

A typical winch launch yeilds about 1/3 of the runway/field available,
this is a fantastic result, Bill!
Perhaps we should be measuring the launch as a percentage of field
length, then there would actually be a record available for everyone to
shoot for, regardless of locality.
So...
With a runway of 3100m and a launch of 1718, the current known record
is 55.42%


Get out there and break it!!

950m steel cable + 350hp winch + 20km/h wind + ASK21 = 750m or 78%.
More high was possible, but airspace class C begins at 750m above our
airfield so I had to release the cable.

I think the ASK21 gets the best high on winchlaunch. Our DG1000 always gets
25% less high.

Greetings,
Sönke

On Nov 28, 6:22 pm, "Sönke Gutzlaff" wrote:
950m steel cable + 350hp winch + 20km/h wind + ASK21 = 750m or 78%.
More high was possible, but airspace class C begins at 750m above our
airfield so I had to release the cable.

I think the ASK21 gets the best high on winchlaunch. Our DG1000 always gets
25% less high.

Greetings,
Sönke

Sönke, what speed do you fly at on the winch, and how much back
pressure do you apply to the stick?


Dan

On 28 Nov., 22:15, Dan G wrote:
On Nov 28, 6:22 pm, "Sönke Gutzlaff" wrote:

950m steel cable + 350hp winch + 20km/h wind + ASK21 = 750m or 78%.
More high was possible, but airspace class C begins at 750m above our
airfield so I had to release the cable.

I think the ASK21 gets the best high on winchlaunch. Our DG1000 always gets
25% less high.

Greetings,
Sönke

Sönke, what speed do you fly at on the winch, and how much back
pressure do you apply to the stick?

Dan

We broke this record with 1718 Meter and a 3030 Meter runway (winch
length)
With NO wind condition. (sometimes even tailwind)
In the spring we do some more attempts for a higher record.
Then we wait for better wind/weather conditions.
We had a Notam and a privat airspace till FL70 for the lost month. on
our next attempts we hope to disconnect the cable at FL70

A winch start to 1718 Meter or a higher has some problems to overcome.
Think about wind directions at higher altitudes sometimes 180 degrees
different from ground wind.
Think about the cloud base. in most of the attempts we had to abort
the winchstart halfway due the lower cloudbase.
What happens if the cable brakes at high altitudes?

The winchstart itself takes about 2 min 20 sec. then you still have
about one minute to winch up the rest off the cable.
driving the cable back to the start position, takes about ten minutes,
so a high production would be difficult.

We had a Notam and a privat airspace till FL70 for the lost month. on
the next attempt

"Dan G" schrieb im Newsbeitrag
...
On Nov 28, 6:22 pm, "Sönke Gutzlaff" wrote:
950m steel cable + 350hp winch + 20km/h wind + ASK21 = 750m or 78%.
More high was possible, but airspace class C begins at 750m above our
airfield so I had to release the cable.

I think the ASK21 gets the best high on winchlaunch. Our DG1000 always
gets
25% less high.

Greetings,
Sönke

Sönke, what speed do you fly at on the winch, and how much back
pressure do you apply to the stick?

Around 100km/h and the stick full pulled back (I know that's not the optimal
position).
Another helpfull fact is, that the wind is getting stronger when you get
higher so the plane is flying like a kite.
But there are only 1 or 2 days during the year when we have such perfect
wind. Normaly we are reaching around 500m with the 21.

Sönke

On Nov 29, 8:13 pm, "Sönke Gutzlaff" wrote:
Around 100km/h and the stick full pulled back (I know that's not the optimal
position)

Judging by your results that's optimal ;-). However at 54 knots and
full back stick you must have been fairly close to the stall. With the
K21's hook being pretty much on the CG point (unlike, say, a K13's
quite forwards hook) I'd worry about what happens on a cable break. If
you were really switched on I expect it would be fine but with a
moment's hesitation you could end up very nose-high without much
speed...


Dan

"Dan G" schrieb im Newsbeitrag
...
On Nov 29, 8:13 pm, "Sönke Gutzlaff" wrote:
Around 100km/h and the stick full pulled back (I know that's not the
optimal
position)

Judging by your results that's optimal ;-). However at 54 knots and
full back stick you must have been fairly close to the stall. With the
K21's hook being pretty much on the CG point (unlike, say, a K13's
quite forwards hook) I'd worry about what happens on a cable break. If
you were really switched on I expect it would be fine but with a
moment's hesitation you could end up very nose-high without much
speed...

I've learned that 100km/h is fast enough, our instructors even say 90km/h
ist the perfect speed for the 21 to gain maximun high.
I had lot of cable breaks this year and no problems with the speed. You've
only to react fast enough. And the 21 is a very friendly flying plane (with
our other planes, especially the ASW19 I prefer higher speeds on winch
launch) and you normaly are not pulling the stick full back before you reach
the safety high.

On Nov 29, 10:24 pm, "Sönke Gutzlaff" wrote:
I've learned that 100km/h is fast enough, our instructors even say 90km/h
ist the perfect speed for the 21 to gain maximun high.
I had lot of cable breaks this year and no problems with the speed. You've
only to react fast enough. And the 21 is a very friendly flying plane (with
our other planes, especially the ASW19 I prefer higher speeds on winch
launch) and you normaly are not pulling the stick full back before you reach
the safety high.

What do your instructors say about using back-stick in the K21?

I just did my annual winch-launch checks and mine wouldn't let me use
any back-stick at all. A K21 will still launch perfectly well like
that but I *know* that I'm not getting the best out the launch like
that. On the other hand my instructor did play a neat trick on me - he
distracted me by suddening say "look at that plane!" and pulling the
release at the same time. I *did* hesitate in getting the nose down
and even though it was only a small delay by the time I'd finished the
push-over to the recovery attitude there was only 40 knots on the
clock. Took a fair few seconds to get the speed back up before braking
down to a straight-ahead landing.

That was a bit of an eye-opener, to be honest.


Dan

Well, if you have the stick fully back (which I often have, and don't object
to with my students), you
1) are above safety altitude
2) pay attention.

Bert

"Dan G" wrote in message
...
On Nov 29, 10:24 pm, "Sönke Gutzlaff" wrote:
I've learned that 100km/h is fast enough, our instructors even say 90km/h
ist the perfect speed for the 21 to gain maximun high.
I had lot of cable breaks this year and no problems with the speed. You've
only to react fast enough. And the 21 is a very friendly flying plane
(with
our other planes, especially the ASW19 I prefer higher speeds on winch
launch) and you normaly are not pulling the stick full back before you
reach
the safety high.

What do your instructors say about using back-stick in the K21?

I just did my annual winch-launch checks and mine wouldn't let me use
any back-stick at all. A K21 will still launch perfectly well like
that but I *know* that I'm not getting the best out the launch like
that. On the other hand my instructor did play a neat trick on me - he
distracted me by suddening say "look at that plane!" and pulling the
release at the same time. I *did* hesitate in getting the nose down
and even though it was only a small delay by the time I'd finished the
push-over to the recovery attitude there was only 40 knots on the
clock. Took a fair few seconds to get the speed back up before braking
down to a straight-ahead landing.

That was a bit of an eye-opener, to be honest.


Dan

Dan G wrote:

What do your instructors say about using back-stick in the K21?

The same as in any other glider: Use as needed to keep your target speed.

"S??nke Gutzlaff" wrote:

"Dan G" schrieb im Newsbeitrag
moment's hesitation you could end up very nose-high without much
speed...

best precondition to safely fly a hammerhead while actively releasing
remainder of cable since you certainly strictly adhered to:

launch) and you normaly are not pulling the stick full back before you reach
the safety high.

http://en.wikipedia.org/wiki/Aerobatic_maneuver