Towing – why and how we do basic training via tow
All courses include tow instruction with our pay-in/pay-out fully hydraulic winch. The advantage of a fully hydraulic system, the most expensive of all winches, is that tow forces can be precisely regulated at all times. This greatly adds to the comfort and safety for the towed pilot.
Here is a tow of a new student (Hunter Davis) and some typical tows at the turf farms (video by Steve Crye). Shelley Ballard-McKinlay created this fun video of towing at the turf farms. Here is an hour long video of a recreational "high tow" on Highway 9 in south central New Mexico (video by Steve Crye). Of interest is the launch and landing, in particular.
The winch has a 25 HP twin cylinder engine that is direct coupled to the hydraulic pump, the heart of the system. Hydraulic fluid is routed through various valves to a servomotor connected to a 3' diameter aluminum drum which holds 10,000' of an extremely strong and durable line called Spectra. The servomotor is heavy duty and is commonly used to drive the front wheels of four wheel drive farm and industrial tractors.
The tow force is adjusted by varying the hydraulic pressure to the servomotor by a special valve (in the right hand of the tow operator in the photo below). The tow operator (TO) also has a hook knife with which he can quickly cut the tow line, if needed. The TO maintains constant contact with the towed pilot via radio. The pilot and instructor have backup radios in case one fails. If all of the radios become inoperable, there are physical signals that can be used between the pilot and the tow operator. Just the same, pilots are instructed that if, for some reason, they cease to hear commands they must immediately release from tow and land safely.
Pay-in mode is done typically at the turf farms. The line goes out from the winch to a truck 1/2 mile away on the other side of the turf farm. the truck has a 15' mast with a pulley at the top. The line goes through the pulley and then all the way back to the winch. In this way, the TO is right next to the pilot during the launch segment of the flight and can adjust the tow force (or stop it), accordingly.
Pay-out mode is typically done from Hwy 9 in southern New Mexico, an isolated country highway approximately 40 miles long that has sparse traffic, no power lines, no crossroads. The winch (on its trailer) is pulled from behind a truck and the line pays out as the pilot is pulled from the ground into the air, just like a boy running and launching his kite.
When being towed up at the turf farms, landings can be made in virtually any direction, depending on wind direction. Under tow, pilots climb from 500' to over 1,000' above launch (the grass of the turf farms).
Here is a typical reading from a student pilot who carried a variometer showing the climb rate and maximum altitude reached under each tow. In this tow, the pilot climbed at about 400-500 ft/min reaching an altitude about 700' higher than launch. How high the pilot gets with a pay-in tow depends on wind speed at launch and time of day. Getting higher means more time in the air to do training maneuvers. The advantage of the tow system is that we can simulate many of the various conditions pilots will experience at a launch site without most of the hazards.
Towing from flat ground rather than running off a steep hill or cliff is generally much safer. It is less daunting for new pilots, especially. However, the safety of a tow depends entirely on the TO and why it is extremely important that the tow be conducted by a qualified and experienced operator.
Under tow, the launch can be stopped at anytime unlike launching from a hill, especially during the critical first 3-10 seconds of the flight. Pilots being towed also have more time in the air as compared to launching from a typical 300' hill. Wind direction does not matter when towing as it does when launching from a hill because we train at huge circles and can locate the towing equipment at any point around the circle so that the direction of tow is into the wind. In addition, such common events as a cravat (collapse and fold in the outer portion of the wing) can be introduced in the glider while it is on the ground. The pilot can then be launched with the cravat (always a modest one) and practice flying the glider. Once a safe height above the ground, he can work the stabilo line in attempt to remove the cravat. Over the years, we found towing to be easier and more pleasant for everyone.
However, all pilots must learn to launch from a hill or mountain site and our training program requires it.
Launching under tow. Photo by Steve Crye
How to launch via towing is also an important skill to have before attending SIV clinics. At these clinics, a pilot is towed 1,000’s of feet into the air over water in order to safely practice special maneuvers that might be needed in flight. Pilots who learn towing at clinics for the first time can be distracted and surprised by the tow operation itself. As a result, they can lose focus on the main purposes of the clinic.
Weather often makes towing the difference between PG pilots staying on the ground or flying. A training hill only works with winds from a certain direction. When we tow, winds can be from any direction or calm. We are fortunate to have the space in this region to offer this unique resource without having to travel for half a day. Our towing areas are in Santa Teresa, NM.
PPG PILOTS Being towed for the first time can be a safer and more relaxed environment for new powered paragliding pilots. Learning how to control both the paramotor and glider at the same time while launching can be overwhelming. Instead, the pilot can be towed up to altitude with the paramotor OFF, disconnect from tow, start the engine, and fly away. With this technique, the way too common hazard of getting the paraglider and lines wrapped up in the propeller can be avoided.
Hooking up to the tow line. The orange drogue parachute is connected to the tow line. It helps us find the end of the tow line after the pilot disconnects in flight. Pilot safety is our primary concern and everything is done with that in mind.
We are pleased to offer this valuable and unique resource in all of our basic courses. All towing is done by USHPA certified operators. For more advanced pilots, we can do a pay-out tow where we pull the winch behind a truck and payout the tow line to the pilot. With almost two miles of line, we can get pilots nearly a mile off the ground. A hang glider pilot who was recently towed up with our equipment commented, "This was the safest towing I have done in all my years of towing...and I started towing in January 1978."
Pilot's view of a tow shortly after launch – on his way to 9,000' MSL. Photo by Steve Crye.
Steps of a typical pay-in tow
- Pre-flight & launch preparation – The pilot prepares for the flight by first doing a safety check (pre-flight) with the help of the instructor/tow operator (TO). A special tow bridle is
connected to the pilot's harness which has a quick release handle that can disconnect the pilot from the towline at anytime. The TO ensures that the pilot is ready to fly and all safety
equipment is present and working correctly, including radio communications. The TO chooses the correct weak-link for the pilot's weight.
- Pilot to tow tech to instructions
Take up slack Pilot repeatedly extends one leg out to the side and back into the center
Pilot stops leg movement and braces self with both feet Ready to launch Pilot makes a single forward bend at the waist Increase towline tension Pilot repeatedly flaps both elbows or arms up and down Decrease towline tension Pilot repeatedly scissors both legs out to the sides and back into the center Imminent release Pilot spreads both legs out to the sides (a BIG scissors) and holds them there
- Layout – The pilot will lay out the glider behind him. Depending on the wind speed, he may face forward for a forward inflation (calm – light winds) or he may
face towards the rear for a reverse inflation (light winds or greater). Most new pilots are more comfortable doing forward inflations until they have practiced their kiting skills.
- Towline – The pilot is hooked to the towline. Between the towline and tow bridle there is a weak-link of the proper size so that if there is some problem during the tow,
such as the towline suddenly jamming, it will break and disconnect the pilot from the tow. There is also a bright orange drogue parachute attached between the weak-link and the tow line to
aid in recovering the tow line after the tow. It also allows the TO to easily spot the end of the tow line in order to bring it back to the launch area. The tow line stretches out about 1/4 mile in
front, then goes through a pulley mounted high on a truck, and then all the way back to the winch which is very close to where the pilot begins the tow. The tow operator has a special knife (hook knife) that he
can use at any time to instantly cut the towline, separating it from the winch, if there is some problem during the tow.
- Forward inflation launch – When the pilot is ready (and is doing a forward inflation), he will bow deeply to indicate that he is ready to launch. The TO will
never launch the pilot until he is certain that the pilot is ready and wants to launch. After bowing deeply (he is ready to fly), the tow
operator will slowly increase the pulling force on the towline. Typically, to make the launch quick and easy, the pilot will resist the tow force by leaning back against the force of the
towline. When the force becomes irresistible, the pilot will lunge forward and run with all his strength. The glider will popup overhead. At this time, the pilot may need to apply brake on
one side or the other to ensure that the glider is flying in the forward direction. If it is and all things looks good, the tow operator will continue the tow, gently increasing the tow force
as the pilot is running forward. If the winds are calm (most often), the pilot may run 10-20 yards during which time the lift on the glider will increase and the pilot will feel it in the
harness. If the winds are calm (most often), the pilot may run 10-20 yards during which time the lift on the glider will increase and the
pilot will feel it in the harness. As often as not, the new pilot will think, "I'm flying! I'm flying! Wheee! I'm flying!" – and promptly sit down in the harness. But
there is not enough lift and he will be sitting on the ground, bouncing along for a second or two while the glider dives forward. The tow operator will stop the tow – and we
must start over. Aborting the launch at this time is harmless. Depending on how the pilot feels, we may try things again, take a break, or quit for the day.
Thankfully, with forward inflations the glider almost launches itself, requiring minimal input from the pilot.
- Reverse inflation launch – If the pilot is doing a reverse inflation, he will inflate (bring up) his
wing and, facing backwards, kite it for moment in order to check everything. When he is ready, he will turn forward. This tells the TO that the pilot is ready to launch. The tow
operator will gradually increase the tow force as the pilot begins his launch run. Depending on the level of training desired and the conditions, the tow operator may have the pilot run a
long distance or short. Running a long distance might be typical of a launch from a shallow sloped site and it will require the pilot to both stay directly under the glider and control its
direction while he is on the ground. It is a great workout to run across the field and then very slowly leave the earth.
- Tow force during launch – Before the pilot's feet leave the ground, the tow force can be next to nothing (experienced pilots) or very strong (new pilots). The reason
for a strong force for new pilots is that the glider will come up quickly and stabilize faster, making it easier for the pilot to get safely in the air. More experienced pilots need the
skills and experience of controlling the glider and less towing force will require them to watch and control things more carefully and deliberately. Despite whatever the tow force is, the exact moment
the pilot's feet leave
the ground, the tow operator must instantly back-off on the tow force to the point where the pilot is just climbing out (100'/min.) Why is this? There are two serious hazards when
towing. One is known as lockout and the other is an uncontrolled surge of the glider when close to the ground which is typically
caused by a break of the weak-link. The latter hazard (uncontrolled surge) is what must be prevented during launch and why the tow force must be decreased when the pilot's feet leave the ground. Also,
gently lifting the pilot off the ground will prevent parachutal stall (where the paraglider becomes a parachute with a much greater sink rate). If there is a
break in the weak-link, for example, the glider will be just a little bit behind the pilot as he rises but not far behind. If it is far behind and the line breaks, the glider will
quickly surge forward if not stopped by an application of the brakes.
In the next moment of an uncontrolled surge, the pilot will immediately begin to swing under the glider and down. At altitude this would be a relatively benign event but when near the
ground the pilot could hit the ground while swinging forward with enough force to be fatal. Only after the pilot is high enough where a sudden release of the tow force would not result
in him swinging into the ground, is it safe to increase the tow forces enough so that the pilot climbs up quickly. In any case, tow force should never result in the glider being more
than about 40 degrees from the vertical behind the pilot. While full stall (but not parachutal stall) is virtually impossible under tow because of the physics, a sudden release of the tow force is still frightening to
the pilot. Such an event can lead to panic and is something we take the greatest pains to avoid in interest of pilot safety.
- During the tow – Once the pilot has left the ground, he has only ONE job and that is to ensure that the glider and the tow line are perpendicular to each other.
This means that he must be looking up at the glider (the tips) and then down to the tow line while making adjustments with one brake or the other as needed. New pilots are so overwhelmed
that they usually are incapable of knowing what to do, even if thoroughly briefed beforehand. This is why new pilots are given two radios attached directly to the helmet right next to
the ears so that the TO can give them the correct commands on how to keep the glider and tow line perpendicular.
- If the tow goes wrong – What happens when the tow "goes wrong"? If the pilot, for whatever reason, cannot keep the glider and the tow line perpendicular to each
other, the glider
will begin to enter lockout. Uncontrolled lockout is exceedingly dangerous! Referring to the boy with the kite, everyone knows what can happen to a kite. In the air, it may
turn sharply to the left or to the right and then, if the boy does nothing but continue to pull on it, it will quickly dive towards the ground and hit with tremendous speed. A
paraglider or hang glider will do the same, usually with fatal results to the attached pilot. At first, the glider gets a little off perpendicular with little change in attitude.
But as it continues to veer away from the direction of tow, the forces increase as the square of the difference in the angle off the perpendicular and both glider and pilot begin to head for the ground
with increasing speed, like the
Thankfully, the remedy to lockout is simple, foolproof, and quick: immediately stop the tow. The moment the tow stops, the glider will immediately – and safely – stabilize directly over the pilot's head, where it should be. This is the passive safety only present in paragliders. If a pilot does absolutely nothing, the wing will fly overhead at trim in a straight line through the air. TO's must be thoroughly trained and certified to know exactly what to do in an emergency. What if the pilot does a sudden 180 degree turn while under tow? The glider will enter lockout very quickly – so quickly that the TO may have to cut the line.
Typically, new pilots who are towing for the first few times have difficulty keeping things lined up and, as a result, the TO will have to stop the tow and wait for the pilot to fly "straight" (the direction of tow). If it does not happen, the TO will instruct the pilot to release from tow, if he is able to respond in that way, and then land somewhere. At the turf farms, we have hundreds of clear acres for pilots to land. Most new pilots require two or three tows to learn how to fly their gliders correctly while being towed.
- End of tow – The end of tow can be any time the pilot desires. There can be many reasons why a pilot wants to get off tow. He may feel airsick or encountered
rough air. Sometimes he may be so nervous that he wants to end the flight ASAP. Experienced pilots may sense a thermal and need to get off tow so they can grab it and fly
up and away. It does not matter the reason because there is no time when a pilot cannot safely LET GO of the brakes and pull the release lever. Ordinarily, we desire the pilot to
release at the highest part of the tow. This is usually when the pilot approaches the "turn around pulley" that is attached to a high mast fitted on one of
the trucks. If he flies past this point, he will begin descending and the TO will have to release the tow by letting the tow line drum free-wheel or by cutting the line.
a.) TIME TO RELEASE As the pilot approaches the point where he wants to release from tow, the TO asks that he performs a big "scissors kick" with his legs so the TO knows he is about to release. The TO backs off on the tow force to lessen the surge of the glider after it is released from tow.
b.) LET GO of the brakes. You cannot pull the release handle AND hold the brakes at the same. To do so may cause the glider to stall (another extremely dangerous event) because he will have to bring the brake toggles why down and past the karabiners.
c.) LOOK for the release handle and grab it. Use the OTHER hand to grab the tow bridle strap that does NOT have the release handle.
d.) PULL the release handle. The drogue parachute and tow line will usually drop away.
e.) SEPERATE STRAPS With BOTH hands, separate the tow bridle straps. Why do this? Rarely, the release line will form a friction knot that might prevent the tow line from disconnecting from the bridle. Sometimes pilots can get confused and yank on the straps rather than pull the release handle. They then might have to reach down and unclip the karabiner that connects them to the tow line. There is no danger because the TO knows they are having trouble and have stopped the tow or, in extreme situations, have cut the tow line. In case things jam at the turn around pulley or at the winch, the weak-link will break long before the tow line can cause dangerous lockout.
In this video, the new pilot experienced nearly total panic when attempting to release from tow – an easy task that he practiced on the ground. He got free eventually but it demonstrates what can happen to us when we get in the air.
- Flying away – AFTER the tow, the pilot will use his hands to get comfortable in the harness and THEN reach up and grasp the brakes. It is then we will do maneuvers.
- Getting ready to land – The first thing a pilot MUST do before landing is to stand up in the harness when he is about 100' above the ground. He is not quite
vertical but his feet are down and ready. When he is a few feet or less above the ground (depending on the type of glider), he may bring his hands down 7"-10" to start slowing the glider
down. Right before his feet touch the ground he must pull the brakes all the way down as far as he can. This will flare/stall the glider and it will stop moving forward and,
depending on the glider type, it may "jump" making the landing a softer one. Once he lands, it is important for him to keep his hands down. He may then turn, face the glider, and
gather it up (rosette it). He may also release all brake by raising his hands the moment his feet touch the ground and kite the glider for as long as he wants. More detail on how
to land safely and comfortably can be found on this page.
- After landing – At this time, the pilot should quickly rosette his glider because winds in the LZ can suddenly re-inflate the glider, pull the pilot over, and drag him. This is not a worry at the turf farms but at your typical LZ, it might matter!
All new pilots (including those having discovery flights) should review Dixon White's notes on towing before being towed. The course fees include instruction on how to be towed safely. Paraglider pilots will receive the "surface tow" special skills USHPA certification upon completion of the P2 or higher course. Powered Paragliding certifications do not have a specials skills certification for towing.
Below, a student pilot demonstrates perfect form at launch from tow. Note the position of his hands – they are even in height and close to the pulleys (full up position). He is still pushing on the "A" lines (but just barely now) to give the wing the speed it needs to get overhead. In a second, he will release the "A" lines and have only the brakes in his hands. He continues to run. In 4-5 seconds he will leave the ground! The orange object is a drogue parachute which helps recover the tow line after the pilot disconnects. The white line across the photo is the other end of the tow line that comes from the "turn around" pulley a quarter of a mile away. Paragliding is easier in the beginning stages because the glider – basically – flies itself.
Here is a complete explanation of how towing works (Courtesy of the Hang Gliding/Paragliding Association of Canada).
A major disadvantage of towing is the much greater expense and only one pilot can be in the air at a time. However, the safety and convenience of towing makes up for this.
Launch events with PPG
Events such as timing the throttle on the paramotor, inflating the wing, staying under it, preventing the glider from diving to one side or the other, and enduring the noise of a fully powered engine can be a bit much for the beginning pilot. So how do we fix this issue?
With our special training technique we add new events one at a time when the pilot is ready rather than overwhelm him with a host of new tasks at the same time. We begin with a simple launch and landing – all under tow, in a straight line, and with no paramotor (or, in the case of wheeled PPG, the engine will not be running). Then, step by step, we increase the necessary tasks required. This method of instruction increases pilot safety and helps prevent damage to the equipment. Training for wheeled powered paragliding is slightly different – contact us if you have any questions.
Training at a hill still has advantages, such as being more like what a pilot actually does at a mountain site.
What end of tow looks like to the pilot. Photo by Steve Crye