Not that kind of wench

[100 pop-culture points to anyone who gets the reference in the title]

Years ago, there was a hang gliding school in Connecticut called Tek Flight Products. They stopped doing instruction about a decade ago, but some of the Connecticut pilots had learned there, and remembered that they had a static winch. This is a device for getting a hang glider into the air without a mountain or a tow plane, and some folks from the club talked to the proprietors and arranged to acquire said winch. There was a minor problem that nobody knew how to operate it or to get towed up with it.

Last year, they scheduled a clinic, and arranged for an experienced tow instructor to come down from Ontario and provide a remedy for that. Unfortunately, several weekends of unsuitable weather got in the way, and the clinic had to be postponed. I had thought that it might happen in the spring, but it wasn’t until autumn that arrangements could be made. About 15 pilots signed on, three consecutive weekends were chosen (in the hopes that one of them would work), and the instructor was again contracted to help us out. The schedule was for an evening of classroom instruction (held at a yoga studio owned by my friends Charlie and Rhonda (thanks!)), and two days of hands-on at Good Hill Farm airport in Roxbury, CT.

The instructor was the venerable Michael Robertson, of High Perspective. He gave us several hours of instruction and demonstrations of how the tow line release works, with the main emphasis being on the communication and safety aspects of the whole operation. One of the pilots in attendance appeared to be skeptical of the very concept, and was there perhaps primarily to save the rest of us from ourselves, but he did show up the following two days and participated.

I was a little late arriving Saturday morning (we were scheduled to start at 8 AM), but that was okay because there was a bunch of stuff that needed to be done before we were ready to start. Kevin had been doing some maintenance work on the winch, but he still had some issues to work out. The winch uses a two-cylinder Briggs & Stratton engine, that runs a hydraulic pump. That in turn drives a hydraulic motor that provides a controlled torque to the winch drum. The result is a constant tension in the tow line, which provides some significant safety advantages over other forms of towing, in particular, if the pilot gets off line, the tow forces will not increase, and as a result there are virtually never weak-link breaks. This particular winch is pretty old, and has some shortcomings. One is that the lever that adjusts the hydraulic pressure is very short, thereby not providing for subtle control, so one of the first orders of business was to add an extender (a piece of tomato stake attached with ductape and zip ties). The winch also does not have a level-wind mechanism, so it was going to be up to the pilots to stay centered on the winch so that the rope wouldn’t all pile up on one side of the drum. And the rope that was on it was some braided yellow poly stuff, not the preferred Spectra line, but that wouldn’t be a big deal for the introductory towing that we’d be doing.

With this big crowd of newcomers to this aspect of hang gliding, we were fortunate that Jon A came down for the first day. He had worked with Michael in the past and has extensive winch towing experience, so he was able to be the first test pilot, as well as giving instruction at launch while Michael operated the winch. The wind on Saturday was a bit cross, coming primarily from the NW (the runway is oriented almost directly N-S), so we had to set up the tow diagonally, which meant that the winch was significantly downhill from launch, and we wouldn’t be able to have very much tow distance. I started out observing from the winch end, and Jon set up for the first tow. The first thing that we learned was that the engine on the winch is too loud, such that the winch operator could not hear anything on the radio. We started out with me standing about 10 meters away so that I could hear the radio, and relaying the calls with hand signals, though later we switched over to having a flag man at launch to do the signalling.

Jon’s first tow was successful, except that he got only a few feet off the ground, despite the fact that Michael was running the winch full-out. That didn’t portend well, although we consoled ourselves with the knowledge that Jon, who is quite tall, was likely the heaviest pilot in attendance, and that for initial training, we didn’t really need to get very far off the ground anyway. But it did suggest that maybe this winch would not meet our expectations of being able to tow us up to soaring altitudes. Jon did another couple of short tows to work the bugs out of the system, then others of us stepped up for a try. We had several Falcon 170 and Falcon 195 wings set up to share, thanks to the generosity of their owners, and were using training harnesses that Michael had brought along with tow releases already set up on them.

video by Steve W.

Early on, we had a pretty sketchy operation going. The winch was underpowered, the pilots had trouble remembering the verbal signals to give, many couldn’t remember that the harnesses we were using didn’t work well if you moved your hands to the control bar, communication was dubious, the winch operator couldn’t see launch very well due to the shape of the terrain, etc. Plus we were towing downhill, and HG pilots don’t like to be facing a downhill landing, so most were releasing very early, after just a few seconds. At least one started on a too-small glider and got dragged across the field on the wheels. I had one try where I got too far off line at the beginning and had to abort because I was heading in the wrong direction. After a bunch of this, we fired up the grills and took a break for lunch.

Two positive things happened during lunch. The first was that the wind straightened out some, so that we were able to set up the winch in a better spot that would allow us to tow almost parallel to the runway. The other was that a couple of the pilots who have some skills with hydraulics looked the winch over and found some adjustments that they could make to increase the tension. Jon took a tow, and it worked! He was able to get up to some more substantial altitude. In particular, he was able to get high enough to transition.

Transitioning is something that happens in winch towing, but not in aerotowing. For the initial low tows that we had been doing, the winch was always out in front of us, just like a tow plane would be. But when you winch tow higher, the line starts pointing further and further downward. The problem with this is that the control bar is in the way. Initially you need the tow line to be above the control bar, but eventually it needs to be below the control bar.

The solution to this is “transitioning”. The tow line ends in two pieces, one longer than the other, and the chest release has two levers. The short line passes above the control bar and connects to the upper lever, and the longer line, which is initially slack, goes under the control bar and connects to the lower lever. When towing, the tension is initially in the shorter upper line until you get to an altitude where it’s pushing down on the control bar. At that point you hit the top lever to release it, and the lower line takes over. This allows you continue until you’re directly over the winch, if conditions permit.

Things started going more smoothly as everyone got used to the process, and a few other pilots tried tows with transition. Woz got one tow that allowed him to turn around, fly back, and land close to launch (there was almost no wind at this point). The afternoon was wearing on, and we were using as much daylight as we could, and I grabbed a glider and went for one as well, deciding to try a transition even though I hadn’t been up since the short, tentative tows of the morning. I got off the ground cleanly, and was determined to stick with it, taking the tow up until the operator dropped the tension, and turning back toward…


I glanced to the west, and the ridge just beyond the edge of the airport was exploding with some of the most intense fall foliage I’ve ever seen. I’m colorblind, but this still blew my socks off. I managed to keep my attention on what I was doing, and landed very close to launch, minimizing the effort of getting ready for the next pilot up.

We also had a moment of anxiety and excitement. One pilot went for his first transition tow, successfully did the first release, then as he approached the winch, the operator dropped the tension, and the rope streamed back behind him where he couldn’t see it. He thought that it must have somehow released, so he just started flying the glider, as everyone on the ground looked up in horror as he was still trailing the rope. We were dreading the possibility that he’d catch it on something on the ground and find himself pulled into a nosedive, or snap it on the electrical wires along the road. Normally the winch operator would grab the hook knife and cut the line so that it would at least not go taut if he flew too far from the winch, but… there was no hook knife there! The winch motor was shut off, and Michael started yelling “RELEASE!! RELEASE!!”. The pilot said that he couldn’t make out what was being said, but he could only think of one reason why somebody would be yelling at him, so he hit the release and all was well. It was probably only 10 seconds or so, just enough to make everybody more careful.

We regrouped the following morning at 8 AM (well, I was a little late again), and we had some changes. First, the hydraulic pressure had been increased even more. Second, the wind was a bit stronger, and now blowing directly out of the south, so we’d be towing in the opposite direction, and could use the entire runway. Third, Michael had added some additional rope that he had brought so that we could manage longer tows. And importantly, Larry took charge of whipping a little discipline on us, in terms of what our roles would be, and what the proper protocols were. This allowed the operation on Sunday to work much better.

There were plenty of jobs to keep everyone busy. At the winch end, Michael started training the local pilots to run the winch, so there was an operator plus someone observing and keeping the log sheet. At the launch end, there was the pilot, plus another pilot getting ready. One person was in charge with a radio to let launch know who was up next, what he weighed, what glider he was flying, and what the flight plan was(the latter quickly became “full tow with transition” for everyone). There was also a flagman giving signals to the winch operator once the engine was running, and a retrieve driver on an off-road go-cart, ready to grab the end of the tow line after it was released, and pull it back to launch for the next pilot. I had done a bunch of retrieve driving on Saturday, and did a lot on Sunday as well, and also put in a lot of time as flag man.

Instead of the five gliders and wandering harnesses that we had used the day before, we switched to using three gliders: a Falcon 170 with a small harness, and two Falcon 195s with medium and large harnesses. We kept the harnesses connected to the gliders, and with efficient line retrieval and pilots generally able to land close to launch, we were able to get fast turnarounds and a lot of flights for everyone.

video by Michael S.

Jon wasn’t able to come the second day, so I stepped up for the first tow, and made an educational mistake. We had a couple of false starts until we got the communication worked out, so that by the time I got into the air, I had forgotten about the transition. I suddenly remembered while I was on my way up, and though I actually had plenty of time, I hastily reached for the release and inadvertently released both levers. It’s easy to do that, and with good reason, because you want to be able to get off the line quickly in case something goes wrong. In fact, it takes a bit of technique to release just the top line, and I did it wrong. No big deal, it just meant that my flight was short. I did a couple of others that went fine, though the wind was picking up and I got a little uncomfortable with the level to which I was getting bounced around. No real need for anxiety, because the nature of the towing equipment minimizes problems in that regard, quite unlike aerotowing.

Another lunch break, this time featuring some delicious homemade sausages, courtesy of Justin, and we were back at it for the afternoon. After a stint as winch operator, Kevin came to the launch end for a tow, and because he wanted to know how high we were managing to get, he strapped on a vario, which was fortunate, because he hit the sweet spot of the day. It had heated up enough that there were some thermals (high clouds came in a bit later and shut that down), and with the vario, he was able to take advantage of them, hanging on for a 27 minute soaring flight, the only one of the weekend.

Michael himself came down for a tow, once he had confidence that the winch operators were competent on their own. And finally, as the clock was winding down and Michael wanted some time for a debriefing, I got a little greedy and slid into line for one last flight. Wanting to cap the day off better than I had started it, I was careful to do everything right, and stayed on the line until I was directly over the winch and they dropped the tension, at an altitude that was 892 feet above launch according to my GPS. Not bad! I milked some time out of the sledder, then carved some expressive S-turns near the ground, and topped it off with a sweet no-step landing.

Winch towing does look like it has a lot of potential, and it has some surprising differences to what we’ve been used to. You get off the ground very quickly, and the climb rate is impressive, even with this relatively low-end winch. The piloting on tow is quite unfamiliar, because we’ve become accustomed to almost always pulling in to some degree, but while under tow you need to let the glider fly at trim. This starts even before launching, because whereas we’re used to being told to keep the nose low when foot launching at mountain sites, here we were constantly telling pilots to get the nose higher. Once flying, the trim nose angle is also very high, which can be disconcerting. The angle of attack is still normal, because the airflow is based on the direction of travel, and “down” from the glider’s perspective becomes the direction of the tow rope, though the pilot still feels normal, “real” gravity. And the chest-mounted release mechanism is a new piece of gear to get used to.

The weekend was a complete success. There were no mishaps, no injuries, nothing worse than grass stains (well, there was one minor rope burn to a leg that happened in the last couple of feet as the rope was being pulled back to the waiting glider). And Michael proclaimed us all successfully trained in stationary winch towing. There is another aspect of it, step towing, that will allow us to get higher, but we didn’t expect to get to that, and there’s tentatively a club trip planned up to Ontario next year to learn how to step tow, once we have more experience and are comfortable towing with our own gliders and harnesses.

As a nice bonus to cap everything off at the end, we were treated to an impromptu airshow by two local biplane pilots.

Saturday: flights 3, airtime 30 sec, 30 sec, 90 sec
Sunday: flights 6, airtime 30 sec, 2m15s, 2 min, 2 min, 3m15s, 4m20s


About cleversky

Hang glider pilot in New England since 2004. Also an avid orienteer, and an embedded systems firmware engineer. And some other outdoor stuff.
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