Author: Lee Estingoy
Edition: Model Aviation - 2009/05
Page Numbers: 50,51,52,53,54,55,58,60,62
,
,
,
,
,
,
,
,

State of the Sport — Aerotow Tips and Tricks

by Lee Estingoy

AEROTOW IS A BLAST! It’s one of the few team events in RC flying. It mixes big sailplanes and big powered models and their pilots on the field. As such, aerotowing does require a slight expansion of the standard RC skill set. The fundamentals are the same, but the consequences of errors can be much more expensive, because the models are generally pricey.

I’m going to share an interview that I held with my aerotow alter ego, Bud Tuglee, as a means of introducing those who are interested in aerotow to some of the day-to-day considerations—the ones most pilots have to learn the hard way. Bud is a highly skilled builder and pilot; he’s been to at least two aerotows, and he usually has one of the biggest models at the field, so he must know what he’s doing. His heart is always in the right place, even if his thumbs aren’t. So fasten your seatbelts; this is going to be an adventure!

LE: I hear that you are working on the definitive treatise on aerotow. How’s it coming? BT: Yep, almost done. There’s always something more to learn—some nuance or technique I pick up that I need to add as another chapter. You never quit learning about soaring or people, do you? I’m currently on the third annual book-release tour promoting it; I guess I need to finish it. I have gotten the title done; it’s going to be Aerotow for… LE: No! You didn’t name it Aerotow for Dummies, did you? BT: Relax. It’s Aerotow for Sailplane Pilots. LE: Okay, I guess that isn’t too bad. No two days at the field are ever the same. Are there some generalities that can make those days more enjoyable for all? BT: I’ve been to quite a few aerotows through the years, and they can be a lot of fun and very successful when participants respect their personal skills, their equipment, and each other.

The sailplane pilot’s goals are to keep the model’s wings level and to keep it above and behind the tug. Anything else results in potential for wild speed undulations, because the glider can rocket around on the end of the towline. Passing the tug is considered bad form. The author’s 1/3-scale Duo Discus was built with flaps, which allow steeper approaches and more precise control of landing speed and point of touchdown. Those are important considerations for a model spanning 22 feet.

2009 Aerotow Event Schedule

LE: What about the tugs? Those are generally large models powered by gas engines. Few sailplane pilots have much experience with them. How does that work out? BT: True, there are skills that need to be picked up. It's nothing that a little time with your gear won't solve. Pilots need to learn basic safety skills that are required for handling large propeller-equipped airplanes.

Always have a helper hold the model; never become complacent.

Hey, Lee! Remember that time you started that tug with your wife holding the airplane for you? LE: Don't go there, Bud. BT: What did you do? You forgot to turn on the radio in the airplane, didn't you? I think that was it. That thing blasted to life at full throttle. What a hoot! The look on your face was priceless.

That airplane dragged your wife across the field on her knees before you figured out that you needed to hit the kill switch on the fuse. She was hanging on for dear life. Has she ever been back out to the field? LE: Nope. That was her last aerotow. How many times are you going to tell that story? BT: A little defensive there, eh? It's a great example and it had a happy ending. Lighten up. LE: I guess. That was my first day flying that model, and it still had a few bugs. I wanted to fly it out there so everybody could see it; I was extremely proud of it. I've done that a couple of times now. If I could do it over, I would have worked out the bugs at my home field and debuted that silly thing when it was ready.

Building these models takes longer than the time you have before the big event. Start early or skip flying that airplane until it's ready. There's always another aerotow unless you've smashed the model. Back to the questions, please.

Aerotow sounds like a tricky thing. How do you know whom to ask for advice? Everybody at the field has an opinion, and there are tons of pilots online. The signal-to-noise ratio is not too good. BT: That's a tough one. I suggest that you use common sense. Ask the pilots who are successful—not the ones who play doctors on TV, if you know what I mean. The fliers with the most expensive gear or the embroidered shirts are not always the ones with the best aerotow skills.

Be careful of the free advice online. There's no telling who's making some of those posts or how long they plan to stay in the country. Find a successful group of fliers in your area and hang out with them for a few days.

LE: How do you keep a tow organized? It seems that glider pilots are often free spirits; there's no telling when they might just start circling in the air. BT: A bit of organization goes a long way.

At a club event, common sense is really all you need. At a larger event, there should be a field marshall—a traffic cop who's responsible for watching the activity and prioritizing the use of the runway.

The sailplanes that need to land must have priority. They can't go around for another try. Once the field is clear, the field marshall can signal the tug and glider to set up. Make that as quick as possible.

When the team members are ready to launch, they should check with the field marshall and search the sky in the direction of launch one more time, to make sure that no sailplanes are in the sky in the direction of the tow. Then away you go!

Glider pilots must follow the tow pilots' instructions while on tow. Neither flier should allow external pressures to force a decision on any matter of safety. Never ignore the voice in your head saying that something isn't right. Never assume that the flier with the flashy airplane or the big attitude knows what he or she is doing.

There's nothing wrong with a tow pilot's declining to pull up a particular sailplane or vice versa. But be nice about it.

One of the best tow pilots I've ever flown with is Mike Frickey, who is a quiet cat. Following is the typical tow conversation for us. Mike: You ready? Bud: Let's go. Mike: You done yet? Bud: Yeah, guess so. Off.

Nobody's going to say that Mike is a poet, but everything was there. He was in charge; when he was finished with the tow, he asked me to get off the line. And I did. There was no chatter, no whining to go higher. These are sailplanes; you're supposed to use thermals, not the tug, to go up high!

Keep both models in comfortable visual range. Sure, you can see them when they are specks in the sky, but you have little ability to judge climb angle or speed way up there. As a tug pilot, the hardest part is keeping things stable at a huge distance. There's no need to go there.

Tug: what to look for

BT: Bigger is better for tugs. Smaller tugs are more affordable and convenient, but there is a sweet spot for tow models that are larger than 25 pounds; something like that will probably be powered by a roughly 100cc engine.

I have been part of a team that easily towed a 50-pound sailplane with a 1/4-scale Cub running a 50cc engine. The extra power and mass of larger tugs provide a margin of safety when things get exciting, because a more powerful tug can muscle its way out of a bad situation.

Another consideration is that the takeoff and climb will be shorter with more power. Less time on tow means less chance for an accident.

Keep the tug simple. Make sure you have easy access to all switches and that you can easily see the fuel level from outside the model.

Make it rugged. Tow aircraft generally incur a ton of takeoffs and landings; a great deal of stress is involved. Make it easy to live with. Removable stabilizers go a long way toward making a model easy to store and transport.

Consider putting an effective muffler on the tugs. I've been to some aerotows that sounded like Kansas City the day after an ice storm—nothing but that obnoxious chain saw noise all day. Mufflers are readily available and they work well; they even add power in many cases. Show some consideration for the neighbors at the field. We don't want to bother them!

Sailplane: what to look for

BT: Bigger is better for sailplanes too; a 5-meter span is optimum. The number-one reason for aerotow accidents on launch is lack of ground clearance for the sailplane and its wingtips. Bigger wheels and more ground clearance on the larger gliders make launching much simpler.

Smaller sailplanes have tiny wheels or no wheels. They have little ground clearance for their gear doors and wingtips. The little models tend to snag in the grass, often with disastrous consequences. I've also seen gliders snag wingtips because the wings flexed from minor bounces.

LE: Can a pilot participate if he or she has a smaller sailplane? BT: Sure, but I strongly recommend that those types of models use a launch cart. They dramatically improve any sailplane's launch success.

A well-equipped club tow pilot or aerotow event should consider such carts to be a vital part of the necessary equipment. Many beginners will not have a cart, and a failed launch at their first aerotow may be the end of their involvement in the segment.

There's nothing manly about a cart, but it beats the walk of shame with your sailplane in a body bag.

LE: It sounds like the takeoff can be exciting. What should the tow pilot be concentrating on at that time? BT: Great question! There's generally 75 feet of line between the tug and the sailplane. It's hard to watch them both and still fly the tug. Do your best with your peripheral vision, but the focus must be on the tug.

I keep a finger on the tow-release switch. I even consciously practice hitting the switch so I can do it as a matter of reflex. You don't want to fumble with switches at this point. You don't want to hit the throttle kill switch either; that doesn't do much for your sturdy tug-pilot image or the front of your airplane.

This may sound silly, but the tow pilot's instinct when things look out of whack is to cut the tug's power. That's not always the best reaction, especially if the airplanes are already moving along at a good clip and the glider catches a wingtip.

It becomes the tow pilot's judgment call when to pull back on the elevator and horse the pair off of the ground with thrust or dump the sailplane and save the tug by pulling it up on power alone.

A good event director will set the ground rules before things get started. That way, no one feels like one pilot is favored over another, when the intent is simply to practice safety.

LE: Tell me about what to do on the climbout. BT: Once airborne, things are generally easy. The tow pilot should keep the tug in a climb that maintains a comfortable speed for both the tug and the glider.

The only thing the sailplane flier needs to do is make sure that he or she keeps the wings level and the model slightly above the tug. The glider will inevitably follow the tug around turns—assuming that the tow pilot makes gentle turns.

Some of the high-performance sailplanes are entirely capable of outrunning the tug. Keep the nose up on the sailplane and it will stay where it belongs: above and behind the tug.

Never allow the sailplane to sink below the tug; the line will likely pull the tug's tail down and put the tug into a steeper climb. The pair will inevitably slow down and things can get silly.

One thing that I find works well is to put a little camber or flap in the sailplane before takeoff. Many of the high-performance sailplanes have nice flaps—use them! Just a little, maybe 10°. This provides more lift to get the sailplane off the ground earlier. It also makes the sailplane fly higher on the line, keeping it well above and behind the tug.

Landing pattern and field considerations

LE: Tell me about the landing pattern and field considerations. BT: Landing is the only mandatory part of a flight, right? It’s relative. It depends on the number of airplanes in the air and the amount of free space on the field. Rely on the field marshall to schedule landings at a big event.

Tug pilots can orbit in a holding pattern if there are sailplanes that need to land, and therefore need the field to be clear. Similarly, tug pilots need to land after the tow—not fly around doing aerobatics; those are distracting to the sailplane pilots. If the tug pilot wants time on his or her airplane, do it before the event.

Since there may be people or airplanes on the field, it is a good idea for the sailplane pilot to ask for a landing slot a while before he or she needs it. Plan ahead and commit to the landing; don’t goof around, trying to be a hero with the low-level thermal at the end of the runway. You’ll likely be in somebody’s way at that point. You can always get another tow.

All of my sailplanes have flaps, so I can come in a bit high, saving altitude in case the field is not clear. Then I can land rather slowly, but not all gliders have that ability. Make the best of the situation and keep safety in mind at all times.

The most important thing to do at this stage of the flight is to get your gear off the field as quickly as possible. I swear I’ve seen some pilots out there combing the hair on their cute little pilots. Don’t mess around with your sailplane; get it off the field.

If the model is too big for you to handle comfortably, because you have a bad back or something, don’t be too proud to ask for help. There are usually a few fliers nearby who would be happy to help.

LE: That’s a lot of advice. You seem to have this all sorted out. BT: Aerotow should be fun. Safety and consideration for others go a long way in keeping it enjoyable for everybody. See you at the field!

Lee Estingoy [email protected]

Sources:

Transcribed from original scans by AI. Minor OCR errors may remain.