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

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

(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

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.

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?

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

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.

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

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

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

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...