Flatlands Tow Tips

By Terry & the `Locals'

1994
Rewritten June '96
Edited '99 & '00

Foreword

 This article was written with the following system in mind:

Skyting tow bridle
Fixed length rope
Motor vehicle for towing.

However many of the points discussed apply to other types of hang glider towing
systems. I have seen various systems come and go in the Flatlands over the
years and the `KISS' car tow has remained clearly dominant - more than
90%. It wins on all accounts - cost effectiveness, simplicity, ease of training an
operator, initial financial outlay and able to acquire equipment to assemble a
system at short notice.

Those who have been flying the Flatlands for a few years or regularly tow in a
group on weekends will be familiar or identify with many of the points raised in
this article.

Collectively our team has well over 4000 tows and has developed these
guidelines over 11 years of towing together recreationally and in the
Flatlands. The main thrust is efficiency and convenience, through preparedness
and anticipation of problems ..... to fine tune team work.

It is not a guide on how to learn to tow and assumes you are already familiar
with basic procedures and safety obtained from a tow endorsement course.

 So don't just stand about! Why aren't you hooked onto that tow rope!!

Len Paton

For the Pilot:

1 Equipment Ready

Make sure all your equipment is functional and preflight checks are
done before lining up to hook onto the tow rope:

 Radio can Tx & Rx, ie battery not flat.

 Mike or headset plugged in.

 Able to lock on mike.

 Bridle attached to correct points, waist and keel.

 Release is functioning.

 Release line for Skyting bridle not too short which will cause a
premature release as the glider rises off your shoulders.

 Bridle untangled and stowed tidily, ready to hook on.

 Hang check.

 Weak link ready.

Do a radio check before the driver leaves for the other end (start point). The
driver could be sitting at the other end of the tow strip, oblivious to your radio
problem.

You should be hooked on and completely ready by the time the driver is
attached at the other end otherwise you will be a hindrance to the team. If
there are a few disorganised ditherers in your team have a second pilot also
ready to go.

Make sure all equipment you need is out of the tow car before towing begins. In
a competition, once the towing starts, do not engaged the driver in a discussion
about your last tow or stop the car to get some equipment out. The driver
should be focused on one thing – to get back down to the end of the rope ASAP
and declare “ready to take up tension”. This also applies when there are more
than 2 pilots towing recreationally. A lot of accumulated time can be wasted.

2 Vehicle Through-way

Leave the launch spot clear until the driver has dropped the rope at launch. This
allows the driver to come right up and drop the rope in the correct spot,
continue through the launch area and do a U turn behind launch. The pilot will
still have time to carry the glider to the end of the rope and be hooked on before
the driver is ready at the other end. This avoids such things as:

the rope being dropped short of launch;

 the vehicle having to manoeuvre and driving over the rope to turn around;

the need for another person to pull the rope up to the hang glider or;

the pilot moving forward to hook on and obscuring their view of the windsock or
streamer.

3 Standard Radio Procedure

Follow a standard routine radio procedure:

Acknowledge each other's primary transmissions. It can be worrying to a
nervous pilot when they hear no response to a request. ("Is my radio
working?!!")

Give your driver warning before you say "go, go, go", for example "picking up
glider" and wind conditions.
It is a common mistake for nervous pilots, when hearing the driver has hooked
on and waiting, to simply pick up the glider and say "go, go, go".

4 Pretension

The pilot should decide how much tension or lack of (s)he wants to start with but
should always take up tension to approx 15 kg first. Do not launch without
having pulled out the bridle firmly away from the pilot. I have seen some
experienced pilots (not tow) take off with one arm over the top bridle line to the
keel. This usually ends in a ground loop and a broken upright. I've also seen
the top rope caught under the side of the helmet and pull a helmet or headset
off. Also if the release line is too short, or is wrapped around the base bar or a
grass tussock, taking up line tension will reveal this. This is preferable to an
accidental release after you say "go, go, go" and having to get the rope back for
another attempt. If the driver is not ready to take up tension, walk backwards
with your glider to pretension the bridle and lay out your release line.

5 Launch Conditions

The wind does not have to be 5kts straight up the strip for a successful
launch. True, this will allow an easy, effortless launch but on light wind days the
thermal is probably behind you and you will be back on the ground in 5 mins
wondering why everyone else is away 1st tow.

I mention this because after a great day I get back to the pub to hear how a
team only achieved a launch every hour because "the wind wasn't coming up the
strip much of the time". Half the team didn't get away and the others launched
so late that they only flew 10km just before dark!!

I am not advocating launching tail wind. It is just possible to foot launch with up
to a 2 kts of smooth constant tail breeze and the ability to sprint very fast, but it
is very risky in thermic conditions. Also if you get a low weak link break or an
early tow vehicle problem, you'll be landing tail wind as well. A dolly is
preferable in these conditions and reduces wasted launch time in variable

conditions. However with any significant tail wind ie > 5 kph the pilot must
consider landing in these conditions if there is a low weak link break?

These are my personal limits: - from 900 cross - 1-2 kts (kicked dust drifts
about ½ m/s).
- " 600 " - 5 kts.
- " 450 " - 10 kts, etc.

Also consider point #1 in advice ‘For The Driver’.

Turn the glider slightly into the wind ( 10-200 ) but not fully and keep the
upwind wing slightly down.
Be prepared to do a weight shift jab to the side to keep that wing level just as
you launch. As you ground skim you may slide sideways across the ground. It
is not necessary to fly the glider back over the strip but keep the wings level. I
have experienced cross wind launches where I was sliding sideways across the
ground at 10+ kts.
(If you are towing on a road with a fence either side you would need to maintain
your crab angle to prevent drifting onto the fence.)

If you are not very tow experienced, when trying something new like this,
gradually increase your limits of acceptable launch conditions along with your
confidence.
Place a windsock 50 to 100 metres infront of launch to the upwind side to gauge
what type of air you will encounter early on the tow

6 PTT Locked On

Unclip your radio once at a safe height to reduce annoyance to other radio users
(eg 300'). Ensure you have heard the driver or other transmissions to confirm
you have unclipped your mike. The newer radios have a “Time Out Transmit”
which automatically switches off Tx with a warning beep – normal tows do not
take longer than 2 minutes. Because most of the UHF frequencies will be in use
during a competition your team will be unable to change to another
channel. The other unlaunched pilots will be effectively grounded until you
remember or your battery goes flat. In the latter case you will be unable to give
a position report for retrieve; not that anyone will be inclined to go looking for
you.

Local rule - Leave your mike clipped on and you buy a carton of beer for the
team.

7 Hang vs Prone

With a Skyting bridle, if you are comfortable in semi-hang while on the tow, stay
in semi-hang until you release. Feet in your harness (to stop pendulum swing),
knees bent and hands on the uprights to give more lateral control, making it
easier to dampen out oscillations leading to a lock out when a thermal pops a
wing up. Also your helmet stays clear of the top bridle line when higher on the
tow.

8 Release under Tension

When in lift, release immediately even with full tow line tension. Many pilots call
out "stop stop stop" and wait for the tension to drop before releasing. Too
late!! The thermal is behind you and on marginal days, chances of finding it are
slim. Releasing under tension usually ensures your release operates cleanly
anyway. Releasing with no line tension is a habit from winch tow training to
prevent wire tangles. If you have a stretchy bridle and a heavy release
mechanism on the end of your bridle, you're more likely to get a nasty surprise
with a low altitude weak link break, not at hight.

Never loose contact with the lift. This golden rule with any competent mountain
pilot also applies to towing. Even a disorganised slow thermal will get better. As
long as you are going up, even very slowly, stay with itunless you are drifting
outside of a glide back to launch. If you op for a relaunch it may be another
hour before your next tow. With the remote start gate there is usually no
disadvantage in a slow initial climb.

For the Driver:

1 Pretension & Launch Technique

In different wind conditions the pilot can benefit from different vehicle start
techniques.

In light winds are your pilots getting a lethargic take off, moon walking until the
glider is properly airborne or wafting into the air barely above the stall then
pancaking onto the ground? After taking up the tension perhaps you could try
the following techniques in different wind strengths.

> 10 kph head wind component: start with the "take up" tension (approx. 15
kg).

5 - 10 kph head wind component: After taking up the tension reverse up until
the tension is nil.

< 5 kph head wind component: After taking up the tension reverse up until the
tension is nil, then
another 3 - 5 metres. Don't do this if the tow gauge is mounted to one side of
the vehicle as a wheel will reverse over the rope and may damage the gauge.

Above all, always use maximum acceleration (without wheel spin) until you have
normal towing tension except in strong wind (ie > 20 kph). You might think this
will abruptly snatch the pilot into the air but there is adequate stretch in 600
metres of 5mm rope for this to become just a quick and smooth increase in
tension at the pilot's end.

What happens in a nil wind launch with the standard 15 kgs of pretension? The
vehicle travels about 3 metres in a couple of seconds reaching maybe 10 kph
before the rope tension is enough for the pilot to take their first step for
launch. The glider will have a ground speed of approx 30 kph from the moment
of launch at the same time. So what happens when the glider which is attached
to the tow vehicle with a fixed piece of rope is travelling 20 kph faster? To make
matters worse there is some stored elastic energy in the rope and the glider is
able to accelerate quickly but the 1-2 tonne vehicle can only accelerate
sluggishly especially on loose dirt.

At the moment of launch the above recommendations will have the vehicle
travelling at a similar speed to the hang glider and avoid that sudden loss of
tension just as the pilot leaves the ground. It is the pilots responsibility to
tell you how much pretension or slack (s)he wants or inform you of wind
conditions at launch. Otherwise the general conditions of the day will give you
an idea what type of launch technique may be use.

2 "Airborne!"

Many drivers do not realise that for the first couple of seconds the pilot is
holding back allowing the tension to build up before taking the first
step. Meanwhile the driver who sees the alarming increase in tension hesitates

or even brakes just as the pilot decides to go. Before you can get the vehicle
moving again you may loose most of the tension. This also occurs with dolly
launching, because of the initial high rolling resistance, and since the pilot is
already in prone is more vulnerable if there is a sudden loss of tension as they
rise off the dolly.

In light winds do not hesitate until the tension is at least up to a strong tow
tension. We have found it very helpful if the pilot can say "airborne" when
they are a couple of feet into the air. Only then should the driver begin to adjust
back to normal tension. Before this, accelerate at maximum to achieve a high
tow tension. Consider that up to 20 kg of rope tension is due to the full rope
length being dragged along the ground. At this phase there is less danger of
breaking a weak link than you think.

3 Meter Monitoring & Tow Tension

Always give the pressure gauge 90% of your attention and 10% to steering the
tow vehicle down the strip. Forget the speedometer. Do NOT look in the rear
vision mirror as the tow tension can drop or rise very suddenly and break a weak
link. Be ready to brake the tow vehicle suddenly. The quicker the tension rises
the more urgent a response is required.
The more thermic the conditions, the lower the desired tension. In strong
thermic conditions maintain the tow line tension near 50% of the weak link
rating to give adequate margin to avoid a weak link break. Once the weak link
breaks the tow is finished and the pilot can only make the best of their present
situation. The pilot can aid the driver by telling them they are encountering a
thermal or "noisy air". This warns the driver before any indication on the tow
gauge and if their attention is wandering, brings it back to the tow gauge.

4 Rope Return - U turn

Clear your rope from adjacent strips ASAP and return it to the launch area
quickly. The time proven method is to simply do a U turn without pausing and
head back to launch. 50 kph is a reasonable speed. Stationary ropes are
quickly sliced by other ropes being pulled over them, so keep yours moving. Do
your U-turn away from the side that the rope has fallen towards, so you don't
drive over it or drag the rope across itself. A U turn means you do not have to
leave your mowed strip to find the other end of the rope nor get out of the
vehicle to pick up the end.

However it does mean a different end of the rope is at launch each time.

5 Rope Return - Ahead

Sometimes it may be better to initially drive forward after the hang glider has
released.

a) After an early glider release the glider end of the rope may fall well before the
vehicle start point.
If you immediately do a U turn and return the rope, you may find it trailing off to
one side or doubled back on itself at the tow vehicle end. Ensure you take the

rope forward by at least its own length from the start point before doing the U
turn. If you do find the rope trailing off to one side, as you proceed back to the
vehicle start point, run it through a carabineer attached to the vehicle (like a
pulley) to feed it back onto the tow strip. Make sure any knots will run through
the carabineer. Someone may have to anchor the rope back at launch.

b) Driving ahead initially keeps the whole rope moving and gets the glider end of
the rope off the adjacent strip quicker. The need for this depends on the activity
on adjacent strips at the time, the cross wind and if the rope was released at a
low angle. If you see a vehicle about to drive over your rope, stop momentarily
until crossed, then keep your rope moving so it does not get cut by the rope
attached to the other vehicle.
Driving over a moving rope quickly will not damage it, but don't be in 2 minds
and pause on top of it - you will shred it. Similarly don't stop near a rope so
that it is pulled up to your vehicle and wedged under the tyres. This will also
shred a rope.

6 Driver Cooperation

Know the radio frequency and the names of drivers on neighbouring strips in
case problems occur requiring co-operation.

7 Beside Fences

If your team is towing near the edge of the paddock your rope may drop over
the fence. Continue up the tow strip until the tow rope is pulled off the fence
and back into the paddock before doing a U turn. To judge this, after the rope
has fallen estimate how much rope is over the fence and use your odometer or
trip meter to indicate when to turn around. It is better to go a bit further than
necessary than to leave the rope partly over the fence as you will need to pull it
off the fence by hand on the way back to launch. Check that the rope has
cleared the fence as you drive back. Alternatively, once you have pulled the
rope off the fence you could drop the vehicle end and pull the rope back by the
glider end. This reduces rope wear (and is the technique used when towing on
roads with a fence either side).

Any hardware such as metal rings on the rope ends are likely to flick around the
top wire of the fence and anchor the rope. Keep your speed near 10 kph and
either watch the gauge closely or constantly look behind at the rope for signs of
sudden tension otherwise you may break the rope, damage your gauge or pull
the fence over. It is much safer to pull the rope off the fence with the rope end
in your hand as you continue driving ahead. However make sure that it is not
wrapped around your hand or fingers in case it is suddenly snatched from your
grip. It would be safer to fix a small snap hook to the right rear corner of the
vehicle with a light weak link. This position allows the driver to observe the rope
in the side mirror. 1 strand of #8 twine is approx. 25 kg. Have several weak
links tied to the vehicle ready.

With only a small spliced loop or a bowline on the end of the tow rope and no
hardware, it rarely gets caught on fences, bushes, etc. You can confidently pull
the rope off fences at faster speeds with it still attached to the tow

 gauge. However the pilot’s system to hook onto the rope may leave a snap
hook or ring on the end of the rope.

8 Rope Return after Early Release

If there is an accidental or early release in the first 100 metres of the tow it is
often quicker for an extra person to run forward and drag the rope
back. Remember if the rope was released under tension it may have sprung
forward a considerable distance.

It is usually better for the driver to disconnect the rope, follow it back in reverse,
and then hook on again. This is far better than somebody pulling on the rope
against the vehicle and trying to wave to the pilot to ask the driver to reverse up
over the radio. There is also a danger of reversing back over the tow rope while
still attached to the vehicle and damaging the tow gauge. For this reason it is
preferred to mount the tow gauge centrally on the vehicle rather than to
either side.
If there is no extra person available the driver should (a) drive forward until they
are the length of the tow rope from the vehicle start point and then do a U
turn to return, or (b) drive forward until they are reasonably sure the rope is
straight and pulled back onto the tow strip before unhooking, driving back,
finding the glider end and towing it back to launch. (b) is appropriate if the
glider released very early and reduces wear on the rope.

9 Reversible Rope Ends

Have your rope set up so it can be end-for-ended. This may involve each pilot
being responsible for their own weak link system and be able to quickly hook
onto either end of the tow rope that has no hardware attached.

10 Streamer at Vehicle Start Point

Stand a small windsock or streamer just in front of the vehicle start point. This
makes it easier for the driver to quickly find the end of the rope as (s)he drives
back to the start point, especially when looking into the sun. The pilot can also
ask the driver what the wind is doing near the vehicle as a gauge of thermal
activity.

11 Remote Release

Install a remote release on the vehicle tow gauge which the driver can operate
while driving. The driver will only have to get out of the vehicle once per tow, to
attach the tow rope just before each launch, saving minutes. When returning the
rope to launch, glance behind occasionally to check that you still have the tow
rope attached. It is a bit embarrassing if you turn up at launch empty handed
and also time consuming to find the end again. A remote release also adds
safety if a pilot locks out or gets into other difficulty. Some remote release
ideas: a lanyard routed outside the vehicle to a roof rack above the driver's
window, an arrangement similar to a bicycle brake cable or an electric solenoid
mounted in front of the release.

12 Tow Gauge Weak Link

 Install a weak link at the vehicle end about 50% stronger than the pilot weak
link. This will protect the rope from being damaged if it should snag on a fence
or become tangled with another tow rope. It will also protect hydraulic tow
gauges which are often damaged and loose calibration if subjected to pressures
above full scale deflection. A suggestion is 6 strands of #8 nylon bricklayers
twine. Replace this weak link daily. If you have a remote tow car release
consider what will happen if this weak link breaks. Don't do what others have
done in the past - put the weak link between the vehicle and the tension sensing
unit!

13 Rope Join & Repair

The driver should be familiar with an appropriate in-line knot for joining the tow
rope in an emergency. This knot should be quick to tie and of minimum
bulk. This is to reduce wear while dragging the rope along the ground and to
assist it to run around objects or over a fence. A suitable knot is a "single
fisherman's knot" (Love Knot is a more appropriate name) with approximately
20mm free ends that are easily included in a protective wrap. The following
knots are not suitable: 2 opposing bowlines, reef knot, over hand knot, figure 8
knot, etc. Keep a sharp knife or scissors in the vehicle, and tape to wrap up the
joining knot. Brown packing tape seems to resist reasonable wear and is
cheap. Electricians tape and ducting tape wear too quickly. Cloth reinforced
tape is the best but is expensive (called ‘Duck’ tape in USA).

14 Rope Knots

After release from the hang glider a loose falling rope can put knots in
itself. This is more likely after a high release in light and variable wind
conditions. Typically, knots form near the glider end of the rope as it falls
through itself. Most are within the first 10 feet but may be up to 50 feet from
the end.
The tension of a couple of tows will seat these knots firmly and you will not be
able to undo them.
If ignored the knot will be a wear point leading to a rope break. Glance back
down the rope as you attach it to the vehicle to check for these knots and undo
them then. If you find a knot a bit too late, run some tape around it to prevent
wear.
Similarly but less common, loop-through knots can form anywhere along the
rope.
Cast an eye along the rope as you hurry back to the vehicle end for the next
tow.

15 Rope Storage

Roll your rope up each day before leaving to retrieve the pilots. There is no
guarantee that you will be on the same strip the next day due to wind changes
and strip rotation. The next morning when other teams drag their rope around
the paddock to a different strip over your rope it will be cut in half in less than a
minute. If you are last onto the paddock it could be in several pieces. Similarly
it is not a good idea to leave your rope laid out until you return that evening to
roll it up. There may have been a wind shift after you left the paddock and
every one moved to cross strips. No one is going to roll up your rope in the

 hurry and confusion. Also, at the end of the day, Free Fliers may have a tow in
another direction. Even with towing continuing on the same strips it is possible
your rope could have others falling over it and be damaged or get caught up and
dragged away.

16 Rope Maintenance

Before towing commences each day take a knife and tape and walk along the
rope inspecting it for worn joining knots, accidental knots and pulled strands. It
may only be necessary to add more tape to the joining knots. Otherwise cut out
any problem areas and replace with the in-line knot. This 15 minute chore could
save at best a 15 minute delay in the middle of peak towing time. At worst most
of your rope may be unfindable after a pilot drops it from 1000 feet and/or it
gets caught up and dragged away by another rope.

The best way to join a rope is a butt splice. It gives only a slight increase in
rope diameter thus reducing the wear associated with knots. With protective
tape a splice will last a long time before needing attention.

17 Spare Rope

Have a spare tow rope in case yours is severed and half is dragged away by
another team's rope.

Remember Murphies Law manifests itself most potently during towing.
Do as much as you can to neutralise its effect.

If you are not averaging less than 10 minute turn around times your team needs
to polish its procedures, (disregarding voluntary waiting for conditions). I hate
to rub it in but in the 1994 Flatlands our driver put 4 pilots into the same
thermal one above the other in a release time spread of 12min 39sec without
compromising any safety guide lines.

You have probably realised the driver is really the key person of the team. If
there is any lack of harmony and the driver is not attacking the job with
enthusiasm and anticipation, you are disadvantaged from the start. Cajole,
praise, and charm them and don't be stingy rewarding them for a top effort.