High tow vs. low tow for rough tows (long)

[Mark James Boyd]

While towing for Hollister, I noticed their instructor
really liked to practice slack line.

So for my flight review in Avenal yesterday, we did a bunch
of slack line corrections. We did them during one tow,
but broke the rope. 150' of rope ($12), two schweizer rings ($20),
one tost ring ($35), a carabiner (sp?), two half-wiffle balls,
and a short section of "weak link" then back-released from
the 2-33. It plumeted swiftly into a thankfully barren
plowed field below.

A few tows later, we mentioned to the tug pilot we were gonna
try slack line again. He wised up and took off the weak
link assembly ($68) leaving just wiffle and a $10 schweizer
ring.

After a dozen more slack rope practice tries, we broke
that rope. The ring and 10' of rope back released and
plumetted into another (thank god) barren field.

I'm sure some tractor pulling a tiller will grind some metal
at some point and we may get them back.

I thought about slack line. The real problem isn't
too much pulling, it's the "snappiness" with which the
slack line comes out.

It strikes me that on low tow, as slack line pulls out,
it allows a lot softer recovery. When slack comes out,
the tail of the towplane is pulled low, giving some
dampening. Next the towplane slows a little from the
drag, also good. On high tow, neither of these is true.

Sure, sure, I've read very careful use of spoilers and
yawing the sailplane away from the slack are tried and true
methods. However, even using these, there is still some point
there is so much slack you are going to break the
rope no matter what. A friend mentioned during his
first flight to try to get in wave, he with the experienced
instructor broke three ropes before succeeding.

My question is to those who have towed through rotor.
Have any of you tried low tow and high tow and would
care to tell us if you've found a difference in the
number of rope breaks?

How about the idea of towing low and to the left of the
tug? Ignore for the moment that it would annoy the tug
driver to do this on purpose (except maybe if torque
and p-factor now meant he could just leave the rudders
to flop about). Also ignore for the moment it is
drag inefficient. Would this reduce the possibility
of slack line and/or improve recovery chances even more?

How about other dangers? If the rope breaks on low
tow how would you feel about having it
fly over/around top of the wing/elevator/rudder?
Anyone have this happen?

I'm especially interested in the experiences of wave
pilots and those towing through super heavy thermals...
but armchair analysis is also invited :-]

[Andreas Maurer]

On 4 Dec 2003 14:57:55 -0700, (Mark James Boyd)
wrote:


>So for my flight review in Avenal yesterday, we did a bunch
>of slack line corrections. We did them during one tow,
>but broke the rope.

>Sure, sure, I've read very careful use of spoilers and
>yawing the sailplane away from the slack are tried and true
>methods. However, even using these, there is still some point
>there is so much slack you are going to break the
>rope no matter what. A friend mentioned during his
>first flight to try to get in wave, he with the experienced
>instructor broke three ropes before succeeding.

Within 18 years of gliding I have not heard of a single tow rope break
(nor a weak-link break) on my home airfield. We are doing high tows,
we seldom practice slack line corrections, we have pretty turbulent
days either.

Is it possible that you are using the wrong ropes/weak links?

Bye
Andreas

[Janusz Kesik]

To keep the reply short, I'll only say what I was taught when practising
the "wave tow". First, fly low, well below the propwash. Second: be on
the ball all the time - just "show" the spoilers. Not open them, but just
show an inch of them (unless the the line is slack much which needs
opening them fully to avoid collision with the towplane) and when the
line is about to get straight, close them. Finally, you can always use
some sideslip (yaw?) to keep the line straight. This works, and we were
doing things when my hairs went straight up. [for ones who know how
effective are the Junior's airbrakes, I'll say only that full brakes in a
sideslip with controls fully moved were often not enough to manage all
the situations that the Yak pilot had shown us that day.] :)

Regards,


--
Janusz Kesik

visit www.leszno.pl - home of the www.css-leszno.it.pl

[Mark James Boyd]

In article >,
Andreas Maurer > wrote:

>Is it possible that you are using the wrong ropes/weak links?
>
>Bye
>Andreas

The first rope broke at a splice, not at the "weak link."
When it did break, it came as a bit of a surprise (at
least to me), but was caused by the wrong technique
for slack recovery.

The second rope break happened with what may have been a
2000# strength rope. This one happened more or less
expectedly. We did a lot quite a few slack line recoveries,
correctly, and with progressively more slack. In this
case the rope either broke at the last few feet, or
became unwoven from the ring. In either case, this is
what the tow pilot said is the common break point for
a uniform rope. The tow pilot said it felt like we were
intentionally trying to break the rope, which is not so
far from truth.

I would be surprised if the average gliderport has ever
seen a rope break under "normal" conditions.
If so this would likely indicate rope/weak link
problems. Our procedures that day certainly
were not "normal," but certainly convinced me that
yes, the rope can be broken with poor slack technique or
simply too much slack. The gliderports that
use wave (including Minden) are apparently familiar
with the latter...

I've flown through rotor and soared wave (in a Katana),
but never under tow (self-launch). It's hard for
me to imagine towing through rotor WITHOUT getting
a rope break...

[BTIZ]

We don't spend that kind of money on our weak link... yes.. the rings are
$10-12. the weak link in the rope is cheap..

if you are breaking the actual tow rope because the weak link was removed
(violation of US FAR?) you really don't have a knack for slack line
recoveries..

We use closer to or more than 200ft of rope.. trying to teach on a 150ft
rope gets real "interesting".

When our actual rope breaks (not the weak link) on slack line training.. it
was about due to be replaced anyway. Normally the weak link at the glider
end breaks and the instructor is able to save the ring.

BT

"Mark James Boyd" > wrote in message
news:3fcfbbf3$1@darkstar...
> While towing for Hollister, I noticed their instructor
> really liked to practice slack line.
>
> So for my flight review in Avenal yesterday, we did a bunch
> of slack line corrections. We did them during one tow,
> but broke the rope. 150' of rope ($12), two schweizer rings ($20),
> one tost ring ($35), a carabiner (sp?), two half-wiffle balls,
> and a short section of "weak link" then back-released from
> the 2-33. It plumeted swiftly into a thankfully barren
> plowed field below.
>
> A few tows later, we mentioned to the tug pilot we were gonna
> try slack line again. He wised up and took off the weak
> link assembly ($68) leaving just wiffle and a $10 schweizer
> ring.
>
> After a dozen more slack rope practice tries, we broke
> that rope. The ring and 10' of rope back released and
> plumetted into another (thank god) barren field.
>
> I'm sure some tractor pulling a tiller will grind some metal
> at some point and we may get them back.
>
> I thought about slack line. The real problem isn't
> too much pulling, it's the "snappiness" with which the
> slack line comes out.
>
> It strikes me that on low tow, as slack line pulls out,
> it allows a lot softer recovery. When slack comes out,
> the tail of the towplane is pulled low, giving some
> dampening. Next the towplane slows a little from the
> drag, also good. On high tow, neither of these is true.
>
> Sure, sure, I've read very careful use of spoilers and
> yawing the sailplane away from the slack are tried and true
> methods. However, even using these, there is still some point
> there is so much slack you are going to break the
> rope no matter what. A friend mentioned during his
> first flight to try to get in wave, he with the experienced
> instructor broke three ropes before succeeding.
>
> My question is to those who have towed through rotor.
> Have any of you tried low tow and high tow and would
> care to tell us if you've found a difference in the
> number of rope breaks?
>
> How about the idea of towing low and to the left of the
> tug? Ignore for the moment that it would annoy the tug
> driver to do this on purpose (except maybe if torque
> and p-factor now meant he could just leave the rudders
> to flop about). Also ignore for the moment it is
> drag inefficient. Would this reduce the possibility
> of slack line and/or improve recovery chances even more?
>
> How about other dangers? If the rope breaks on low
> tow how would you feel about having it
> fly over/around top of the wing/elevator/rudder?
> Anyone have this happen?
>
> I'm especially interested in the experiences of wave
> pilots and those towing through super heavy thermals...
> but armchair analysis is also invited :-]

[Mark James Boyd]

In article <rjQzb.7929$yf.258@fed1read01>,
BTIZ > wrote:
>We don't spend that kind of money on our weak link... yes.. the rings are
>$10-12. the weak link in the rope is cheap..
The end of our rope is a schweizer ring. The weak link assembly
is a weaker 3 foot rope with a tost at one end and a schweizer at
the other. A (strong) carbiner connects one end of the weak link
assembly to the end of the rope (schweizer).
We quickly and easily flip the assembly
depending on tost vs. schweizer tow.

>
>if you are breaking the actual tow rope because the weak link was removed
>(violation of US FAR?) you really don't have a knack for slack line
>recoveries..
Hmm... 91.309(a)(3) seems to say the weak link is only required
if the rest of the rope isn't between 80% and 200% of max cert
glider weight. As far as having a knack...that's why we train, eh?

>
>We use closer to or more than 200ft of rope.. trying to teach on a 150ft
>rope gets real "interesting".
We use between 200-300 ft. I guess 240ft is most common. I do
not envy anyone towing on a 150ft rope.

>
>When our actual rope breaks (not the weak link) on slack line training.. it
>was about due to be replaced anyway. Normally the weak link at the glider
>end breaks and the instructor is able to save the ring.
This was the case for us as well...a weak point broke the first
time. The second time we assume it broke near the glider
end because that is where most wear occurs in the rope (hookup,
wiffle ball rubbing, etc). But the second time was was not
because the rope was weak, just that that point was the weakEST
part of the rope.

We had a great discussion about doing slack line practice over
unpopulated areas in case the rope breaks with enough left
to drag back and back release.

[Janusz Kesik]

U¿ytkownik BTIZ > w wiadomo¶ci do grup
dyskusyjnych napisa³:rjQzb.7929$yf.258@fed1read01...

> We use closer to or more than 200ft of rope.. trying to teach on a
150ft
> rope gets real "interesting".

I agree: "interesting"... 150ft is a rope used in first flights here
(Poland), the longest. The only situations when we use longer ropes is
the triple tow (30, 50 and 75 metres). I'd rather say, that using the
short rope would make the tow easier. When towing for a typical
thermalling, the 30m (90ft?) rope is just OK, and I often flew with 20m
rope, especially in the mountains - in most cases the tow was easier and
more comfortable to me. Also gaining height (in order to shorten the tow)
by a towplane with glider behind is much, really much easier and less
stressing when using a short 20-30m rope.
When practising the "wave tow" and in real flights throught the rotors,
the 15-20m long rope is used.

The last advice I could give for Mark is: enter the propwash and stay
here. This should make keeping the rope spanned easier.

Regards,


--
Janusz Kesik

visit www.leszno.pl - home of the www.css-leszno.it.pl

[BTIZ]

we just swap out the weak link rope... a simple eye splice on the end of the
"rope" and the end of the link with the appropriate ring on the other end.

don't involve a carbineer...

and if the rope breaks.. you don't loose a $30 tost link AND a $12
Schweitzer link if it back releases..

we have had some rope breaks and the glider brings back his end..

or if the weak link breaks with slack line training.. try to save the ring..

BT


"Mark James Boyd" > wrote in message
news:3fcfe229$1@darkstar...
> In article <rjQzb.7929$yf.258@fed1read01>,
> BTIZ > wrote:
> >We don't spend that kind of money on our weak link... yes.. the rings are
> >$10-12. the weak link in the rope is cheap..
> The end of our rope is a schweizer ring. The weak link assembly
> is a weaker 3 foot rope with a tost at one end and a schweizer at
> the other. A (strong) carbiner connects one end of the weak link
> assembly to the end of the rope (schweizer).
> We quickly and easily flip the assembly
> depending on tost vs. schweizer tow.
>
> >
> >if you are breaking the actual tow rope because the weak link was removed
> >(violation of US FAR?) you really don't have a knack for slack line
> >recoveries..
> Hmm... 91.309(a)(3) seems to say the weak link is only required
> if the rest of the rope isn't between 80% and 200% of max cert
> glider weight. As far as having a knack...that's why we train, eh?
>
> >
> >We use closer to or more than 200ft of rope.. trying to teach on a 150ft
> >rope gets real "interesting".
> We use between 200-300 ft. I guess 240ft is most common. I do
> not envy anyone towing on a 150ft rope.
>
> >
> >When our actual rope breaks (not the weak link) on slack line training..
it
> >was about due to be replaced anyway. Normally the weak link at the glider
> >end breaks and the instructor is able to save the ring.
> This was the case for us as well...a weak point broke the first
> time. The second time we assume it broke near the glider
> end because that is where most wear occurs in the rope (hookup,
> wiffle ball rubbing, etc). But the second time was was not
> because the rope was weak, just that that point was the weakEST
> part of the rope.
>
> We had a great discussion about doing slack line practice over
> unpopulated areas in case the rope breaks with enough left
> to drag back and back release.

[Bruce Hoult]

In article <3fcfbbf3$1@darkstar>,
(Mark James Boyd) wrote:

> Sure, sure, I've read very careful use of spoilers and
> yawing the sailplane away from the slack are tried and true
> methods. However, even using these, there is still some point
> there is so much slack you are going to break the
> rope no matter what.

I've been towed in strong thermals and some pretty serious wave rotor at
e.g. Omarama. I've never had a problem with a big jerk when the slack
comes out of the rope. I don't use spoilers, and I don't yaw. What I
*do* is when the rope is becoming slack I climb (and therefore slow
down). As the rope starts to become tight I descend (and therefore sped
up). Do it right and there is no jerk at all.

Notes:

- make sure you're not still high when the slack comes out. Pulling the
tail of the towplane up is a *bad* thing. In any event, the height
change required is usually not all that much. But if through
misjudgement you are high when the rope comes tight then you should
release.

- if I'd climbed as far as I was comfortable, and was still overtaking
the towplane then I'd use airbrakes. Hasn't happened yet, except on a
deliberate descent.

- I guess it's possible that this might not work as well in something as
draggy as a 2-33. It's great in glass.

[Michel Talon]

Bruce Hoult > wrote:
> In article <3fcfbbf3$1@darkstar>,
> (Mark James Boyd) wrote:
>
>> Sure, sure, I've read very careful use of spoilers and
>> yawing the sailplane away from the slack are tried and true
>> methods. However, even using these, there is still some point
>> there is so much slack you are going to break the
>> rope no matter what.
>
> I've been towed in strong thermals and some pretty serious wave rotor at
> e.g. Omarama. I've never had a problem with a big jerk when the slack
> comes out of the rope. I don't use spoilers, and I don't yaw. What I
> *do* is when the rope is becoming slack I climb (and therefore slow
> down). As the rope starts to become tight I descend (and therefore sped
> up). Do it right and there is no jerk at all.
>

Same for me. I began gliding in Montpellier where there are serious
rotors due to the mistral, and instructors never taught me to do
anything particular (like using spoilers, etc.) in case the rope is not
tight. They taught me to content following the plane as best as
possible, and apparently this doesn't cause big problems. I have never
seen a broken rope either.



--

Michel TALON

[Brian Case]

Hi have been doing quite a few Slack rope demos recently, Mostly in
Blaniks and 2-33's or 2-32's. Also done a few in my HP16T. I have put
huge amounts of slack in the rope, so much so that I have had the rope
back release on both the HP and the 2-32. I have had the 2-32 wingtip
abeam the towplanes tail when the rope finally back released, If it
had not I was planing on recovering. I have yet to break a tow rope.

Typically the rope we use is 200ft hollowbraid Poly rope with no
weaklink. I have used adapters (sometimes called a weaklink to convert
a Schweizer ring to Tost or vi versa.)

My technique for recovering from slack rope is to move way off to the
side of the tow plane (About the Upper left or right corner of were we
box the wake) If going right this puts the left wing tip of the glider
just about behind the right wing tip of the towplane. You can pull up
slightly to help take the slack out but this usually is not necessary.

By moving out the side like this when the Rope goes tight it Yaws the
tail of the towplane and if using a nose hook on the glider will yaw
the glider as well. This yawing of both the glider and towplane
almost eliminates any tendancy for the rope to snap and break.

Brian C.
CFIIG/ASEL

[Hank Nixon]

(Mark James Boyd) wrote in message news:<3fcfbbf3$1@darkstar>...
> While towing for Hollister, I noticed their instructor
> really liked to practice slack line.
>
> So for my flight review in Avenal yesterday, we did a bunch
> of slack line corrections. We did them during one tow,
> but broke the rope. 150' of rope ($12), two schweizer rings ($20),
> one tost ring ($35), a carabiner (sp?), two half-wiffle balls,
> and a short section of "weak link" then back-released from
> the 2-33. It plumeted swiftly into a thankfully barren
> plowed field below.
>
> A few tows later, we mentioned to the tug pilot we were gonna
> try slack line again. He wised up and took off the weak
> link assembly ($68) leaving just wiffle and a $10 schweizer
> ring.
>
> After a dozen more slack rope practice tries, we broke
> that rope. The ring and 10' of rope back released and
> plumetted into another (thank god) barren field.
>
> I'm sure some tractor pulling a tiller will grind some metal
> at some point and we may get them back.
>
> I thought about slack line. The real problem isn't
> too much pulling, it's the "snappiness" with which the
> slack line comes out.
>
> It strikes me that on low tow, as slack line pulls out,
> it allows a lot softer recovery. When slack comes out,
> the tail of the towplane is pulled low, giving some
> dampening. Next the towplane slows a little from the
> drag, also good. On high tow, neither of these is true.
>
> Sure, sure, I've read very careful use of spoilers and
> yawing the sailplane away from the slack are tried and true
> methods. However, even using these, there is still some point
> there is so much slack you are going to break the
> rope no matter what. A friend mentioned during his
> first flight to try to get in wave, he with the experienced
> instructor broke three ropes before succeeding.
>
> My question is to those who have towed through rotor.
> Have any of you tried low tow and high tow and would
> care to tell us if you've found a difference in the
> number of rope breaks?
>
> How about the idea of towing low and to the left of the
> tug? Ignore for the moment that it would annoy the tug
> driver to do this on purpose (except maybe if torque
> and p-factor now meant he could just leave the rudders
> to flop about). Also ignore for the moment it is
> drag inefficient. Would this reduce the possibility
> of slack line and/or improve recovery chances even more?
>
> How about other dangers? If the rope breaks on low
> tow how would you feel about having it
> fly over/around top of the wing/elevator/rudder?
> Anyone have this happen?
>
> I'm especially interested in the experiences of wave
> pilots and those towing through super heavy thermals...
> but armchair analysis is also invited :-]


Our club,Valley Soaring Club in SE NY and the prior 2 commercial
operations have
used low tow exclusively for more than 30 years. It is used in Oz as
primary. Not sure where else.
Our experience is that slack rope situations are almost totally non
existant. Most all of these result from descending from a higher
position.
We teach and fly in a position just below( almost touching the wake).
In this position, the rope is in line with the natural trailing
position behind the tug. As a result, if the rope is released from the
tug, it falls below the glider and will back release in most cases.
Even if way too low the rope would normally just trail over the top of
the glider. Yes the ring could hit the canopy or other part of the
glider.
Advantages we see:
New students fly the tow without help within 2 or 3 tows. Position is
easy to view, evaluate and adjust.
Glider is on thrust line of tug- efficient, less trim drag, no trim
change.
Nobody ever dove a tug pilot into the ground in low tow.
Slack is virtually not a factor. Easily and gently corrected. No
broken ropes. I have not had a broken rope in 10,000 low tows at
glider end and about 4000 at tug end.

Myth: you can get too low and pull tug tail down stalling him- We
tried and found we could actually go slower in control towing with
Super Cub with glider hanging way low than we could with glider off.

Myth: Rope wil tie itself around wing and disble controls if released
at front. Show me a rope that can go upwind in a 60 mph headind.

Conclusion: It is worth learning to do right. Tug pilot needs to be
aware you will be doing something different(he may need mirror
adjusted differently).

OK now all the experts can shoot holes in my comments- go for it.
UH

[Andrew Warbrick]

At 15:06 05 December 2003, Hank Nixon wrote:
>Myth: you can get too low and pull tug tail down stalling
>him- We
>tried and found we could actually go slower in control
>towing with
>Super Cub with glider hanging way low than we could
>with glider off.
>
>Myth: Rope wil tie itself around wing and disble controls
>if released
>at front. Show me a rope that can go upwind in a 60
>mph headind.
>
Neither of these are myths, it actually happened two
years ago at the Cambridge Gliding Club though not
as a result of using low tow. The tug was flying too
slow and the Puchacz on the back got gradually lower,
ending up pulling the tugs tail down as he applied
more and more power, eventually the tuggie released
and the rope wrapped itself around the puch wing (fortunately
not fouling any controls in this case). Both aircraft
subsequently landed safely with no damage.

Although I was present on the airfield I didn't witness
the incident, I did speak to the P1 shortly afterwards,
I'm sure someone from the Cambridge club could give
you more detail.

[Mark James Boyd]

A lot of different techniques - little consensus

Bruce - Hi to slow and get slack out, then match speeds by diving
Brian - Yaw to reduce snappiness when line comes taut
Janusz - Shorter rope so tug and glider are in the same air
Michel - Low tow and avoid slack line

Although Bruce's approach is most elegant, I think it
also requires the most skill and best timing. Matching
airspeeds is challenging.

Brian's approach is pretty standard, but also requires a
little bit of timing. I'd also be surprised if he
isn't subtly using a little bit of dive at the end
to help match airspeeds.

Janusz and his 20 meter rope leaves me speechless.
I'd have to try it to have any real opinion.

Michel's low tow seems like a low-skill winner.
As long as you don't get too low and scare the towpilot
into releasing it seems you'll do ok.

Not mentioned is the use of spoilers. I've noticed
one ranked pilot who flies a slick glider sometimes with
ballast uses slight spoiler adjustment to regulate slack line.

Any rotor towpilots have any further opinions?

[303pilot]

I've heard europeans say this before but I just don't understand. With 200'
of rope I'm roughly 2 seconds behind the tow plane. That's 2 seconds to
construct a response to whatever I see happen to the tow plane. How does
shortening the interval make things easier?

The only case I can think of is if the rope is short enough that the tow
plane and glider experience things at the same time. I guess that's what
you get w/15 meter ropes? Please help me understand why anyone would ever
intentionally get (and stay!!!) only one wingspan (or less with slack) away
from the tow plane.

Brent
(who mostly gets towed through benign 3 knotters, but has experienced 13
knotters and Minden wave/rotor)
"Janusz Kesik" > wrote in message
...
> U¿ytkownik BTIZ > w wiadomo¶ci do grup
> dyskusyjnych napisa³:rjQzb.7929$yf.258@fed1read01...
>
> > We use closer to or more than 200ft of rope.. trying to teach on a
> 150ft
> > rope gets real "interesting".
>
> I agree: "interesting"... 150ft is a rope used in first flights here
> (Poland), the longest. The only situations when we use longer ropes is
> the triple tow (30, 50 and 75 metres). I'd rather say, that using the
> short rope would make the tow easier. When towing for a typical
> thermalling, the 30m (90ft?) rope is just OK, and I often flew with 20m
> rope, especially in the mountains - in most cases the tow was easier and
> more comfortable to me. Also gaining height (in order to shorten the tow)
> by a towplane with glider behind is much, really much easier and less
> stressing when using a short 20-30m rope.
> When practising the "wave tow" and in real flights throught the rotors,
> the 15-20m long rope is used.
>
> The last advice I could give for Mark is: enter the propwash and stay
> here. This should make keeping the rope spanned easier.
>
> Regards,
>
>
> --
> Janusz Kesik
>
> visit www.leszno.pl - home of the www.css-leszno.it.pl
>
>
>

[Bill Wallace]

The only time I have ever seen a tow rope break is during an
intentional rope break manuver. I have been flying the big Nevada and
Eastern Sierra air since 1968, as a glider pilot, tow pilot, air
ambulance driver (rotorcraft). I have thousands of hours flying the
east side in all kinds of conditions (many hundreds of flights in wave
and rotor conditions). Mark, something seems odd about your
descriptions and experiences. Are you getting professional assistance?
Please do not take my post as a slight, as it is not meant to be
degrading.

[Janusz Kesik]

> I guess that's what
> you get w/15 meter ropes? Please help me understand why anyone would
ever
> intentionally get (and stay!!!) only one wingspan (or less with slack)
away
> from the tow plane.

Yes that is the purpose of using such short ropes, but also makes
thermalling in towed flight easier. It also makes keeping glider in the
right position when towet through the turbulent air with lots of 'ups and
downs'. Usually the 50m rope is used at the beginning of the training
prosess, and after getting the licence all the tows are done using 30m
and shorter ropes. Some time ago someone described his own experience
which happened many years ago (in '60s or '70s) at Leszno when came there
as a visitor, took a Pirat for some flying and outlanded. Then he was
towed out of a short field by an Yak-12 which's pilot incredibly
shortened the rope in order to shorten the ground roll as the forest
seemed co be too close to get over it with a 'normal' rope. :))

Regards,

Janusz Kesik

visit www.leszno.pl - home of the www.css-leszno.it.pl

[Janusz Kesik]

U¿ytkownik Janusz Kesik > w wiadomo¶ci do
grup dyskusyjnych ...
Also gaining height (in order to shorten the tow)
> by a towplane with glider behind is much, really much easier and less
> stressing when using a short 20-30m rope.

I meant gaining height in a towplane with a glider behind, by using the
thermal to support the tug's climb rate.

Regards,

JK

[Janusz Kesik]

U¿ytkownik Mark James Boyd > w wiadomo¶ci do grup
dyskusyjnych napisa³:3fd0d41d$1@darkstar...
> A lot of different techniques - little consensus

> Although Bruce's approach is most elegant, I think it
> also requires the most skill and best timing. Matching
> airspeeds is challenging.

For me it looks for a great way to break the rope, but I migth be wrong
of course.

> Janusz and his 20 meter rope leaves me speechless.
> I'd have to try it to have any real opinion.

30m rope is a standard, but when switching for a 20m, it seems a bit
scary for the first time when You can see if the ring at the end of the
rope is properly connected to the Wilga's (towplane) towhook. ;) I'm
joking of course, but for the first time it can look strange. Usually one
gets used to it very quickly.
>
> Michel's low tow seems like a low-skill winner.
> As long as you don't get too low and scare the towpilot
> into releasing it seems you'll do ok.

You can always fly just_in_the_propwash (wake?) as it also helps to keep
controls crisp at low speeds.

> Not mentioned is the use of spoilers. I've noticed
> one ranked pilot who flies a slick glider sometimes with
> ballast uses slight spoiler adjustment to regulate slack line.

It can be used, but very carefully. Don't do this in Pirat, especially if
You're a tiny person. I had some problems with closing the Pirat's brakes
on tow, know at least one girl who wasn't able to close the brakes,
landing at the beginning of the afld. There was at least one accident of
another girl in Pirat caused by large force at the airbrake handle when
towed. But also... wise use of airbrakes in gliders like the Junior or
Puchacz (from my experience) can in most cases solve the problem.

Regards,


--
Janusz Kesik

visit www.leszno.pl - home of the www.css-leszno.it.pl

[Mark James Boyd]

In article >,
Bill Wallace > wrote:
>The only time I have ever seen a tow rope break is during an
>intentional rope break manuver.

Same here. The only time I've ever seen two rope breaks was during
our two intentional rope break manuevers.

>Eastern Sierra air since 1968, as a glider pilot, tow pilot, air
>ambulance driver (rotorcraft). I have thousands of hours flying the
>east side in all kinds of conditions (many hundreds of flights in wave
>and rotor conditions). Mark, something seems odd about your
>descriptions and experiences. Are you getting professional assistance?
>Please do not take my post as a slight, as it is not meant to be
>degrading.

I was very satisfied with my instructor and the instruction we did.
I certainly feel confident I know the difference between textbook
correct and incorrect slack line procedures
(having practiced both intentionally).
I'm also confident that the rope will not break during normal,
and even fairly rough tows with standard technique.
I'm equally confident it will break cleanly if stressed enough
(and will do so without damage to the towplane or glider).
I'm convinced to practice such things over
desolate areas, and I'm convinced the 2-33 will back release
if the rope breaks with 100+ feet of line and
drags back behind the glider (although I've never had the
experience like Brian's back release without a rope break).
Overall I'm quite satisfied with my "professional assistance."

Your question also prompted me to to call back my friend who
had two rope breaks flying into wave in the Sierras. He's
also a pilot examiner for power and a commercial glider pilot
and gave me some more detail, including exact CFIG name and
dates and FBO. I called the FBO (which uses high tow through
wave, by the way), and got some additional confirming detail.
I'm tempted to share what I learned, but perhaps will wait
until I'm able to get an even fuller story and permission
to use names in person from the CFIG up in the Sierras.

The general gist is that my experience seemed not uncommon.
Ropes break where they are worn, which is not always
at the weak leak. Imperfect technique by pilot or
tow pilot may break a rope. It's harder in rotor
because so much is going on.

Bill, your response is relieving, because it suggests you are
an experienced tow and glider pilot in rotor, and that this
experience has made rope breaks non-existent for you.
It's nice to hear that with experience, rope breaks are
not inevitable. Perhaps you could also please share with
us your techniques for towing/being towed through rotor?
To fix slack line, do you yaw? Do you go high/low?
Do you ever use spoilers? Have you tried a low tow?
Do you tow through rotor, or around, over and on top of
the wave? Have you ever released rather than watch
an apparently inevitable rope break?

Sharing your personal experiences would be perhaps be
more enlightening than any of my further comments...
:) Pray tell...

[Bruce Hoult]

In article >,
"Janusz Kesik" > wrote:

> U¿ytkownik Janusz Kesik > w wiadomo¶ci do
> grup dyskusyjnych ...
> Also gaining height (in order to shorten the tow)
> > by a towplane with glider behind is much, really much easier and less
> > stressing when using a short 20-30m rope.
>
> I meant gaining height in a towplane with a glider behind, by using the
> thermal to support the tug's climb rate.

If the combo has found a thermal, why wouldn't the glider just release
and save money?

Therre have been plenty of times that I've intended to tow to 2000 or
2500 ft but then released in a thermal at 1000 - 1500 ft.

-- Bruce

[Janusz Kesik]

U¿ytkownik Bruce Hoult > w wiadomo¶ci do grup
dyskusyjnych ...
> In article >,
> If the combo has found a thermal, why wouldn't the glider just release
> and save money?
When the combo (now I know the word for it ;) starts the first circle at
70m, it's too low I think... :)) Few circles can be useful.

JK

[Andreas Maurer]

On 5 Dec 2003 10:53:17 -0700, (Mark James Boyd)
wrote:

>A lot of different techniques - little consensus
>
>Bruce - Hi to slow and get slack out, then match speeds by diving
>Brian - Yaw to reduce snappiness when line comes taut
>Janusz - Shorter rope so tug and glider are in the same air
>Michel - Low tow and avoid slack line

Let me add the standard procedure that I was told and that all pilots
I know of are using:
Extend the airbrakes (carefully - only about one inch) to get the
slack out. Don't let the speed difference between glider and tow plane
get too big.

>Not mentioned is the use of spoilers. I've noticed
>one ranked pilot who flies a slick glider sometimes with
>ballast uses slight spoiler adjustment to regulate slack line.

Ooops... seems like others are using that method too.. ;)

There's one important part when trying to get the slack out: Do not
let the glider get too slow (compared to the tow plane) - otherwise
the acceleration when the tow rope tautens might break the weak link.

The method of how to slow the glider down is a question of taste -
I've used sideslips for that part which also work well (but I teach my
students to use tha airbrake).


Bye
Andreas

[Bruce Hoult]

In article >,
Andreas Maurer > wrote:

> On 5 Dec 2003 10:53:17 -0700, (Mark James Boyd)
> wrote:
>
> >A lot of different techniques - little consensus
> >
> >Bruce - Hi to slow and get slack out, then match speeds by diving
> >Brian - Yaw to reduce snappiness when line comes taut
> >Janusz - Shorter rope so tug and glider are in the same air
> >Michel - Low tow and avoid slack line
>
> Let me add the standard procedure that I was told and that all pilots
> I know of are using:
> Extend the airbrakes (carefully - only about one inch) to get the
> slack out. Don't let the speed difference between glider and tow plane
> get too big.

And if it does, what do you do then?

That's why if I'm going faster than the towplane I prefer to store the
energy by climing a little, rather than by simply throwing it away using
the brakes, or a slip, or a yaw.

The slack isn't going to come out until you're going slower than the
towplane, and you need a way to get back to about the same speed again.

-- Bruce

[Stefan]

> Let me add the standard procedure that I was told and that all pilots
> I know of are using:
> Extend the airbrakes (carefully - only about one inch) to get the

Try this in a Janus. Extending isn't a problem, but I wish you luck
closing them again during the tow. Chances are that after successfully
closing them, slack is much bigger than before.

Stefan

[Janusz Kesik]

U¿ytkownik Bruce Hoult > w wiadomo¶ci do grup
dyskusyjnych ...
> In article >,

> That's why if I'm going faster than the towplane I prefer to store the
> energy by climing a little, rather than by simply throwing it away
using
> the brakes, or a slip, or a yaw.

But there's a risk that the towplane gets "out of the screen" because You
got higher than it, and then You have a problem...

JK

[Andreas Maurer]

On Sat, 06 Dec 2003 16:59:44 +1300, Bruce Hoult >
wrote:


>> Extend the airbrakes (carefully - only about one inch) to get the
>> slack out. Don't let the speed difference between glider and tow plane
>> get too big.
>
>And if it does, what do you do then?

Pray that I don't break the cable.


>That's why if I'm going faster than the towplane I prefer to store the
>energy by climing a little, rather than by simply throwing it away using
>the brakes, or a slip, or a yaw.
>
>The slack isn't going to come out until you're going slower than the
>towplane, and you need a way to get back to about the same speed again.

Basically a good idea - but higher than the tow plane, especially in
gusty conditions, is a place where I try not to be.

Bye
Andreas

[Andreas Maurer]

On Sat, 06 Dec 2003 11:35:46 +0100, Stefan >
wrote:


>Try this in a Janus. Extending isn't a problem, but I wish you luck
>closing them again during the tow. Chances are that after successfully
>closing them, slack is much bigger than before.

Why?
I haven't flown the Janus that often, but to me its airbrakes didn't
feel extraordinary to me?

Bye
Andreas

[Mark James Boyd]

In article >,
Andreas Maurer > wrote:
>On Sat, 06 Dec 2003 16:59:44 +1300, Bruce Hoult >
>wrote:
>
>
>>> Extend the airbrakes (carefully - only about one inch) to get the
>>> slack out. Don't let the speed difference between glider and tow plane
>>> get too big.
>>
>>And if it does, what do you do then?
>
>Pray that I don't break the cable.

I think perhaps if there is some room to go down without dramatically
pulling down the towplane tail, a slight dive might work, perhaps
a little off to the side to add some yaw/dampening effect

>
>
>>That's why if I'm going faster than the towplane I prefer to store the
>>energy by climing a little, rather than by simply throwing it away using
>>the brakes, or a slip, or a yaw.
>>
>>The slack isn't going to come out until you're going slower than the
>>towplane, and you need a way to get back to about the same speed again.
>
>Basically a good idea - but higher than the tow plane, especially in
>gusty conditions, is a place where I try not to be.

So if you start at low tow or right in the propwash, pulling up a little
won't get you above the towplane as quickly. But we are agreed that
so high one can't see the towplane is bad (immediate release) but
that same angle lower than the towplane is not as sketchy (although
now we have the new worry of possible slack rope around the wing
or a much more exciting rope break).

>
>Bye
>Andreas

So again, in this thread I was mostly talking about rope breaks
in wave instead of thermals. So I suppose it would be nice
to know how standard tows through rotor go. I imagine one
starts under/before the rotor and the first thing the tug hits is
negative shear or a downdraft. If the tug drops, and
glider doesn't drop too, glider is too high and uh oh.
So the glider can either nose down, slip, or use spoilers to
lose altitude and stay with the tug. Nosing down, if done
wrong (too much) means now you've introduced slack, and when
the glider hits the same downdraft/tailwind a few seconds later,
the rope comes taut and snaps.

Now in the rotor, the tug maybe hits an updraft/positive shear.
If the glider pitches up and stays in position, then when
the glider hits the same updraft/headwind a few seconds later,
the glider will be too high and have to use spoilers/slip/nose down
to maintain position.

Spoilers are tricky to use. We tried them during some of
our slack rope practice and the difference between closed and
cracked is dramatic. Diving the nose seems like it might take
a lot of skill to do right. On the other hand, using
a slip to lose altitude is simply, easy to take out, and
has the added inherent "yaw" benefit.

So perhaps flying low tow or right in the wake, and
using slips is the simplist (but not most elegant) technique.
Then watching what the tow plane does and anticipating the same
thing happening to the glider a few seconds later would help.
Eevn on low tow it seems there is some room to dive a
little to get airspeed at the last second if needed.

I plan to go to the Sierras at some point for some wave fun,
and perhaps will try both high and low tows and see how they
compare. Should be fun :)

Mark

PS. The dramatic difference between closed and cracked also
came up from a 10 foot rope break. With the fence coming up,
slowing down is important. I couldn't forward slip (wings
too long close to the ground), so I cracked spoilers.
The plane bounced fairly gently once, and then I closed the
spoilers and landed (although a little long).
It seems at 60-70 mph at 10
feet on rope break, I was better off pitching up to climb and
slow down, and opening spoilers during the pitch up climb.
Cracking spoilers at high speeds has a dramatic effect
(perhaps not surprisingly now that I think about it in
my armchair). It seemed pretty clear that spoilers are
designed for losing altitude, not for slowing down. If they
were designed for slowing down, there would be a pitch up
change when deployed, right?


"rec.aviation.soaring - BS free since Dec 6, 2003 11:45 PST" ;-p

[Stefan]

Andreas Maurer wrote:

> Why?
> I haven't flown the Janus that often, but to me its airbrakes didn't
> feel extraordinary to me?

The last time I flew a Janus, I needed both hands to close the airbrake.
THE girl who flew it the next day even couldn't close them at all, she
needed the help of the copilot.

Stefan

[F.L. Whiteley]

"Stefan" > wrote in message
...
> Andreas Maurer wrote:
>
> > Why?
> > I haven't flown the Janus that often, but to me its airbrakes didn't
> > feel extraordinary to me?
>
> The last time I flew a Janus, I needed both hands to close the airbrake.
> THE girl who flew it the next day even couldn't close them at all, she
> needed the help of the copilot.
>
> Stefan
>
He's taking the Mickey.
Andreas claims " 6'7", 201 cm" ;^)
He once had an image posted, but it appears to be missing now.
He's a big lad, if anything he might have trouble with full aft travel of a
control.

Our elder member, about 135cm, had a little trouble with the airbrake handle
in our Grob when they popped open once.

YMMV,

Frank Whiteley
Colorado

[Bruce Hoult]

In article >,
Stefan > wrote:

> > Let me add the standard procedure that I was told and that all pilots
> > I know of are using:
> > Extend the airbrakes (carefully - only about one inch) to get the
>
> Try this in a Janus. Extending isn't a problem, but I wish you luck
> closing them again during the tow. Chances are that after successfully
> closing them, slack is much bigger than before.

I'm not sure I understand what you're talking about. We've got:

1) a Janus
2) 1000 ft high ridges
3) frequent strong winds onto the ridges
4) airspace limitations restricting us to, say, 2500 ft in some
of the places the ridges take us.

So I've spent a fair amount of time flying the Janus at 90 - 100 knots
and needing some brake to stop from busting the altitude limit. It's
not a problem.

See, for example:

http://www.hoult.org/bruce/gliding/sasha/p17.html

Someone previously asked if I always fly around with the brakes half
open. Yes, on days like that, in that area.

-- Bruce

[Bruce Hoult]

In article >,
Andreas Maurer > wrote:

> >That's why if I'm going faster than the towplane I prefer to store the
> >energy by climing a little, rather than by simply throwing it away using
> >the brakes, or a slip, or a yaw.
> >
> >The slack isn't going to come out until you're going slower than the
> >towplane, and you need a way to get back to about the same speed again.
>
> Basically a good idea - but higher than the tow plane, especially in
> gusty conditions, is a place where I try not to be.

I don't know how much height is required, but I suspect it's on the
order of 5m. On a 50m+ rope that's Not A Problem.

-- Bruce

[Andreas Maurer]

On Sat, 6 Dec 2003 19:50:25 -0700, "F.L. Whiteley"
> wrote:

>Andreas claims " 6'7", 201 cm" ;^)
... did I mention the 95 kilo's...? ;)

>He once had an image posted, but it appears to be missing now.
>He's a big lad, if anything he might have trouble with full aft travel of a
>control.

This is not my problem... the problem is the aft CG... :)

Bye
Andreas

[Brian Case]

small correction, I wasn't suggesting yawing the airplane to slow it
down and take out the slack. What I was saying is if you move off to
the side when the slack comes out it will automatically yaw the
towplane and a nose hook equipped glider. No timing required just stay
out to the side.

Brian


(Mark James Boyd) wrote in message news:<3fd0d41d$1@darkstar>...
> A lot of different techniques - little consensus
>
> Bruce - Hi to slow and get slack out, then match speeds by diving
> Brian - Yaw to reduce snappiness when line comes taut
> Janusz - Shorter rope so tug and glider are in the same air
> Michel - Low tow and avoid slack line
>
> Although Bruce's approach is most elegant, I think it
> also requires the most skill and best timing. Matching
> airspeeds is challenging.
>
> Brian's approach is pretty standard, but also requires a
> little bit of timing. I'd also be surprised if he
> isn't subtly using a little bit of dive at the end
> to help match airspeeds.
>
> Janusz and his 20 meter rope leaves me speechless.
> I'd have to try it to have any real opinion.
>
> Michel's low tow seems like a low-skill winner.
> As long as you don't get too low and scare the towpilot
> into releasing it seems you'll do ok.
>
> Not mentioned is the use of spoilers. I've noticed
> one ranked pilot who flies a slick glider sometimes with
> ballast uses slight spoiler adjustment to regulate slack line.
>
> Any rotor towpilots have any further opinions?

[Mark James Boyd]

In article >,
Brian Case > wrote:
>small correction, I wasn't suggesting yawing the airplane to slow it
>down and take out the slack. What I was saying is if you move off to
>the side when the slack comes out it will automatically yaw the
>towplane and a nose hook equipped glider. No timing required just stay
>out to the side.
>
>Brian
>

Thank you, Brian. A subtle but important distinction...being out
to the side clearly means the slack is taken out with quite a bit
less "snappiness." And this is a different dampening than the
yaw of the glider and tug when the line comes taut. Excellent!

[Caracole]

> small correction, I wasn't suggesting yawing the airplane to slow it
> down and take out the slack. What I was saying is if you move off to
> the side when the slack comes out it will automatically yaw the
> towplane and a nose hook equipped glider. No timing required just stay
> out to the side.
>
> Brian

If we can base the idea on two premises, first that we have a lot of
slack and second that breaking the rope is undesirable.

The reality is that large amounts of slack tend to result in big speed
differentials between the tow plane and the glider, particularly with
glass gliders and powerful tugs.

While the rope is slack, no thrust is transmitted to the glider.
Even with no pitch change, the glider begins decelerating. Due to
the loss of the glider's drag, the tug either accelerates or increases
rate of climb (depending on the tow pilot's actions). Presuming a
beginning generous gust or slap, and big slack, this allows a long
enough time period for a noticeable speed differential to be created.
Now, with differential speed, the slack is coming out rapidly.

One pilot sits level with or slightly below the tow plane and offset
to one side believing that the imminent yawing between the tow plane
and glider will dampen the loads sufficiently to prevent the rope
from breaking.

A second pilot has positioned himself slightly above the tow plane
and offset enough that he can easily watch the towline and it's
rate of tightening. As the line starts to come tight, this pilot
points his nose toward the tow plane and lowers the nose,
believing that he is in a good position and attitude for at least
some of the tow line loads to be absorbed in accelerating the glider.
The speed differential is diminished, as is the AOA of the glider.

Which of these two pilots is least likely to break the rope? And do
you have sound physics (rather than emotion) to support your position?

M Eiler