The Pilot's Lounge #65:
One, Two, Three, Heave
Tired of touch-and-goes in the pattern and begging friends to go for a $100 hamburger? Need a challenge to re-energize your flying? Even private pilots can tow gliders, although a commercial certificate will let you do it for money. AVweb's Rick Durden lays out what it takes to help those engine-less soaring birds.
Despite the ongoing silliness of a Transportation Security Administration that continues to treat general aviation pilots as if they were criminals, it's been a pretty good summer here at the virtual airport. People are learning to fly, a couple new pilots have purchased airplanes and hangared them here, and we've enjoyed the conversations that ensue in the pilot's lounge as those new owners discover some of the joys and challenges of airplane ownership. There continues to be a frustrating turnover as a certain number of newer pilots drop out after only flying a hundred hours or so. I'm always sorry when I realize that someone who had been around here pretty regularly no longer shows up for the informal solve-the-world's-problems sessions or at the occasional evening when we have cold beer and soda and someone totes the barbeque out and we grill burgers. Aviation isn't exactly overpopulated and I miss the folks who drop out.
I made the mistake of mentioning to Old Hack that I was disappointed that I hadn't seen two of the sharper of the new pilots, Mary or Steve, in a couple of months. He looked at me with his long-suffering, "what kind of moron are you" expression, deftly slid his toothpick from the left side of his mouth to the right and growled, "What do you expect? They both liked to fly, but they were tight on money and got bored coming out to shoot touch-and-goes in a Cherokee 140 every two or three weeks and decided it wasn't that much fun. They didn't fly enough to be comfortable in the airplane and they couldn't afford to fly more, so they stopped. It's the same old story -- how come you are so jeezly na´ve to be surprised by it?"
|Ready for Tow (click photos for larger versions)|
As only Hack can do, he stirred things up. No, not his comments about me being na´ve -- that's generally accepted -- but folks got to talking about how to fly more for less money. I heard a number of ideas that made sense such as joining a flying club, flying the least expensive trainer possible, shared ownership, taking friends for rides and splitting the cost of the rental and a few others. About that time, Tony Smit -- who runs the glider operation at Benz Aviation in Ionia, Mich., is one of the best glider instructors I know and who got me back into towing six months ago -- looked at me and said, "Durden, you sap, you know I'm always looking for decent tow pilots. Why didn't you see if Mary and Steve would have liked to tow? I can't pay them unless they hold a commercial ticket, but it's some of the best stick-and-rudder flying around, so why didn't you ask them?"
As usual, Tony wasn't interested in the fact that I hadn't even known what the story was with Mary or Steve. Before I could try to defend myself, one of the other pilots spoke up and asked Tony what was involved in towing gliders and if he could see about checking out to do it.
I listened while Tony explained.
What it Takes to Tow
Of course the regs are the first concern. There are some specialized FARs that relate to towing gliders, but they aren't too difficult. A pilot has to have at least a private ticket, a hundred hours of flying time, receive a checkout and get an endorsement for glider towing. Most tow planes have tailwheels, requiring a tailwheel endorsement, and many have enough power to require a high-performance endorsement. There are also requirements for such things as towline strength, tow signals, emergency procedures and rope drop. If you look at 61.31, 61.69, 61.113 and 91.309 you should find everything you need.
The Soaring Society of America is the activist organization that supports everything having to do with soaring and gliders/sailplanes. It's based in Hobbs, N.M., and has excellent publications and videos for pilots who want to tow gliders. Burt Compton, of the Soaring Society of America and one of the sharpest guys in the soaring world, has published a very good handbook on glider tow that can be purchased -- along with other manuals on soaring -- at his Web site.
|Double Heinkel He-111 Bomber Tow Plane|
Some truly fascinating airplanes have been pressed into service to tow gliders. My favorite, although it's probably good for pilot longevity that it's no longer around, was the World War II Siamese-twin version of the Heinkel He-111 bomber: Two of the twin-engine He-111s were joined at the outer wing panels by a fifth engine. I always thought the F-82 Twin Mustang was kind of funky, but this beast that struggled to tow the monstrous Messerschmitt Gigant glider into the air had to have truly been something else.
|Three Me-110s Pull Me-Gigant (rocket assist motors parachuting down behind)|
The modified Heinkel was developed to replace a truly bizarre and dangerous towing procedure, the "Troika-Schlepp," which was three, count 'em, three, Messerschmitt Bf-110s (twin-engine fighters) in vic formation that was originally used to cause the Gigant to become airborne. Both methods of towing what was then the second-largest aircraft ever built worked poorly, and killed pilots and passengers at an eye-watering rate. In one horrific accident, the three Troika-Schlepp pilots, the six crewmembers of the Gigant, and the 120 troops aboard it perished when things went sour.
Nowadays towplanes are a bit more prosaic than what the Germans were using in the early 1940s; nevertheless, they share the characteristic of having enough engine to allow a decent rate of climb while attached to a boat anchor (a.k.a. glider). The Piper Super Cub has been used for years, with the Bellanca Citabria and its bigger brother, the Scout, proving popular. The Cessna O-1 Bird Dog is an excellent towplane as are the piston-powered ag-planes, such as the Piper Pawnee, Call Air A-9 series, and even the Cessna Ag-Wagon or Ag-Truck. One occasionally sees a Wilga, or even a Cessna 182 or a Piper Cherokee. If there is an STC for installation of a tow hitch for the airplane, it can probably tow gliders.
|Pawnee Tow Planes|
For a private pilot trained in contemporary spam cans, getting to fly an interesting tailwheel airplane with lots of power, even without getting paid for it, is a pretty good thing. If you can be counted on to be available a couple of weekends per month, it's worth it for the glider club or school to check you out in that exotic airplane to tow for them. For you, it's a chance to really refine your stick-and-rudder skills, get lots of takeoff and landing practice and learn to control an airplane precisely.
If you haven't already learned the joys of flying off of grass runways, you will, because most glider operations are from grass runways; grass is not as abrasive on a tow rope as pavement. You will also learn about that rope connecting you to the glider: The tow-rope length is specified by the FARs, as is its breaking strength so as to protect the glider and tow plane should problems develop on tow. Having the tow rope break rather than tearing the nose off the glider or the tail off the tow plane was long ago determined to be the appropriate approach to situations where turbulence or poor pilot technique causes a great deal of slack to develop in the tow rope and then takes it out in short order. As a tow pilot, you are wise to inspect the condition of the rope you are going to be using because they do wear out. You will learn early on that a knot weakens the rope substantially. Part of your preflight of the airplane will be to inspect the tow hook so that you can be sure to be able to release the tow rope should something be amiss and the glider is unable to release. If the glider cannot release, the pilot will pull off to his or her left and rock the wings. You then pull your release and set the glider free. If you cannot release, you make a power reduction and head back for the airport. The glider will go into what is called the low tow position while you set up a long, fairly flat approach, allowing for the fact the glider is below and behind you. The glider will touch down first, and then you do so. The glider will be doing the braking for both of you as you keep to the left side of the landing area; the glider stays right and you pull the mixture to get rid of any residual thrust.
A Typical Flight
|Glider in Rear-View Mirror|
Normal tow operations start with you taxiing to a spot near the front of the glider so a ground handler can attach the rope to your airplane (if it's the first flight of the day, otherwise you generally keep the rope on the airplane all the time) and then walk the rope to the nose of the glider. The ground person will signal you to taxi forward about 180 feet and then stop as he or she attaches the rope to the glider and checks its release mechanism. Once that is done, you will be signaled to take the slack out of the rope by taxiing forward a few more feet. The ground handler will stand at the wingtip of the glider, holding its wing level. Depending on the operation, the glider pilot will either waggle the rudder to signal to you that it's time to go, or will give a thumbs-up to the person on the wingtip, who then looks over the traffic pattern to try and make sure it's clear, and swings one arm in a circle, calling on you to move the throttle from quiet to noisy. Check the rear-view mirror, or look back at the glider one more time to make sure its speed brakes are stowed, and bring the throttle up over about a three-second period to avoid jerking the glider.
As you accelerate, don't assume the person on the ground saw all of the traffic. Especially if there are intersecting runways, be ready for another aircraft to appear suddenly. I've found that I have aborted about 1 in 60 takeoffs when I tow on airports with intersecting runways because of conflicting traffic the ground person simply couldn't see. Making repeated glider tows can lead to complacency, something that can result in much unhappiness.
The glider will lift off well before you do. Assuming all goes well, the glider levels off at about three feet of altitude until you break ground. If the glider pilot errs and continues to climb, it will pull your tail upward with vigor, so be ready to pull the release, abort the takeoff and move left to stay out of the way of the landing glider. It's a very, very rare event, but it does happen.
|Ready to Launch|
Your airplane will unstick at something on the order of 45-55 mph. Depending on the glider you are pulling, you will be looking to tow at a speed somewhere between 55 and 60 for the more basic training ships, to something on the order of 75-85 for the high-performance gliders. Nail the speed as soon as possible and hold it. That can be some work to accomplish, so be ready to do what is necessary and memorize the pitch attitudes for each speed you need to fly. For the training ships you may feel as if you are not all that far from stall speed in the climb. That's only because your feeling reflects reality. Therefore, it's wise to develop the ability to control your speed effectively.
As you climb you are going to be taking advantage of thermals, which means that you will be around gliders that are working the same ones, so it's essential to keep a constant lookout. While an airplane towing a glider has the right of way over other powered aircraft, you do not have the right of way over gliders. It is wise to make fairly shallow turns because you are leading a formation flight and the glider will have trouble staying in position in anything beyond a shallow bank.
Should the rope break during climb, turn left to stay out of the way of the glider. Believe it or not, once you go through 200 feet AGL after takeoff, the glider can successfully turn around and land on the runway. In fact, it can probably glide far enough down the runway to touch down and stop about where the takeoff roll started.
Did You Pull Yet?
Usually you will have been advised as to how high the glider wants to go on tow. Sometimes the glider will release earlier, especially if you go through a particularly energetic thermal. Normally you will feel the release as the tow plane surges slightly. On some airplanes you will hear a bang when the glider pilot pulls the release. There are glider pilots who practice what is known as a "soft release" in which she or he climbs up above the normal tow position, dives to put some slack in the tow rope and then releases. While it is said to reduce the already low risk of a knot forming in the tow rope, the technique has caused more than one tow pilot threaten to shoot the glider pilot down because it is absolutely impossible to tell when the glider has released unless the tow pilot is watching for it in the mirror (and assuming there is a mirror and it doesn't vibrate so badly that it's unusable). With the demands of watching for traffic and monitoring airspeed, seeing the glider release is pretty much blind luck, especially if the pilot has elected to release below the stated altitude.
When the glider releases, it will turn right. You turn the tow plane left and make sure that the release has actually occurred. The next step is to make a partial power reduction, lean the mixture and start a descent. The operator for whom you are flying will prescribe power settings for the descent that have proven to keep the engine temperatures from changing too rapidly. You can usually come down at about 1,000 fpm while carrying some power and keeping the speed in an acceptable range. Watching for traffic is a never-ending process and many tow pilots will make frequent banks during descent to uncover blind spots and present as big a target as possible so that other airplanes in the area can see the tow plane.
|Rick Shows Off the Tow-Plane Sunburn|
When things are busy and gliders are waiting for you, the formalized pattern entry at a 45-degree angle simply isn't something you are going to do. Yes, I know, the 45-degree pattern zealots will raise a stink, but you do not have the luxury of time to do a stylized dance to get into the pattern. Watch for traffic carefully, enter the pattern as efficiently as you can, flying as tight a pattern as possible while keeping in mind that you have a tow rope hanging down at least fifty feet below you and there will be gliders about. Cross any obstructions on final a minimum of 200 feet above them with your speed at a maximum of 1.3 Vso. If the landing area is at all short, slow to below 1.3 while over the obstruction so that you can keep the rope over it, then close the throttle and dive for speed as you approach the threshold, giving you adequate speed for the flare when power off. One of the most pleasant things about towing is that you get to know the airplane so well that you should be able to put the airplane down within a few feet of your desired spot, right at stall speed, thus minimizing your ground roll.
After talking to Tony, and now doing some towing myself, I'm of the opinion it's a good way to keep a person's stick-and-rudder skills high without having to shell out cash, with the excellent side effect of being able to associate with some pretty good people.
See you next month.