In Harmony with the Wind
by Jerry Thomas, EAA Chapter 932 Editor
It has been said that the best way to learn to fly is in a sailplane, where power is provided only by air currents and gravity, and a pilot learns the fundamentals of flight with an incomparable clarity. In a glider, energy management becomes an art and every landing requires precision.
Several weekends ago, I was passing through Harmony, IL when a sailplane appeared, turning gracefully to a hushed landing. As a place, Harmony, is much like our familiar Greenwood, an unincorporated bit of a town that is forced to use a mailing address other than its own. In this case, the USPS considers Harmony to actually be Hampshire, IL.
However you refer to it, it’s home to a grass strip where only sailplanes live.
I stopped to watch, then located the gravel track off of Route 20 that leads to a combination clubhouse/hangar and a grass strip where several sailplanes gathered. The building and adjacent runway belong to Sky Soaring, a club founded in 1972 by a group of area sailplane pilots.
It was a beautiful summer day and a number of people were watching and participating. Exiting the car, I was fortunate to make the acquaintance of John Osborn, a glider pilot, who graciously took the time to explain what was happening and to give me a tour of the club’s hangar. Among other items, that hangar housed a large flatbed truck with a huge engine and a rear-facing seat mounted in the bed. Large metal spools of Spectra rope were attached to either side – one yellow and one red.
This was TOST, a double aero-winch unit from Germany that had been assembled onto the truck bed and used a high-output 450 hp V8 engine to power it. The side drums each held 3,400 feet of polyethylene rope that looked way too thin to pull a 1,200 pound glider into the air. However, John advised me that the Spectra rope is actually stronger and lighter than the steel wire used in earlier days.
On this day, the club was using their C182 tow plane to launch gliders, so unfortunately, I didn’t see the winch in operation. However, John lead me through a typical winch-launch operation.
The truck-mounted winch system is positioned at the far, upwind end of the airstrip. The two drums on either side allow for the staging of two gliders at the downwind end of the 3,400 foot field. The ends of each rope are drawn from the winch to the opposite end of the runway by a “mule” car with a wide, folding cross bar on the roof that keeps the ropes from twisting into a colorful Gordian knot.
Two gliders can be cycled in under 4 minutes. One-half of the length of the rope as stretched out on the ground is approximately equal to the maximum altitude that can be attained by a sailplane using the winching process.
A short rig made up of sections of rope that join a parachute and a “weak link,” is attached between the rope and the sailplane. The weak link, a color-coded piece of steel with a specific shear value, prevents over-stressing the wings during the launch. Each pilot is responsible for choosing the colored link required by his particular aircraft. After the tow rope is released by the pilot, the small parachute provides tension to the line so that the winch driver can respool it in a controlled manner as it falls to the earth.
A ground support team consisting of three people is needed to winch-launch a sailplane: a Wing Runner, a Winch Driver and a Launch Director. The Wing Runner has a number of responsibilities including staging the ropes and their hardware, connecting the rope to the glider and holding the wing level during the launch. The launch itself is controlled by the Launch Director. Using a dedicated phone system, the Launch Director communicates with the Winch Driver at the other end of the field. He also communicates with the glider pilot during the launch. The Winch Driver controls the speed of the rope and manages the power output of the engine with input from the Launch Director.
The Winch Driver receives a 2-minute warning, He starts the big V8 and lets the Launch Director know when the winch is ready. For safety, the tow rope isn’t attached until after the pilot secures his canopy. From that point, the launch is considered to be on. The Wing Runner attaches the rope to the glider then moves out to a wingtip to level the craft and signals to the Launch Director that the glider is ready.
The Launch Director makes a final check for air traffic, insures that the runway is clear and notifies the Winch Driver to take up the slack in the tow rope. As soon as the line goes taunt, the director calls, “GO, GO, GO!” into the phone. At that stage, the only way to abort the launch is for the pilot to pull the rope release. No one else can stop it.
Within the first 2 seconds, the sailplane is airborne, flying level. The use of the word “Launch” is no exaggeration.
As soon as the pilot feels aileron authority, he pulls the sailplane into a 45-degree climb, while carefully watching the airspeed. The Winch Driver receives instructions from the Launch Director to adjust the throttle on the big V8 as needed. The pilot and the Winch Driver have no direct communication. All communication with the Winch Driver goes through the Launch Director.
25 seconds pass. The rope is now at an approximate 70-degree angle to the ground and the sailplane has reached its maximum launch altitude. The pilot pushes the nose over, releases the tow rope and sets a slightly nose-down attitude to maintain airspeed. The glider will also automatically release from the tow rope once the glider goes beyond a 70 degree angle.
A typical launch will achieve 1,000 feet AGL. A good wind from the runway heading may allow it to attain 1,500 feet AGL. The entire flight will last 10 to 12 minutes.
In Spring, when the ground is warming, an experienced pilot, searching out thermals, can extend the air time while flying a considerable distance and still be able to return to the field.
In contrast, the use of the tow plane for an aero-launch will typically take the glider to between 2,000 and 3,000 feet AGL resulting in a flight of 20 to 30 minutes. The higher altitudes make it more likely the glider pilot will find lift and fly away from the field.
The aero-tow process is somewhat less regimented, requiring only two pilots, but if other people are around, one will usually offer to serve as a Wing Runner. An aero-tow will cost the pilot $45, quite a bit more than a winch launch at just $10.
I asked John how long it takes to earn a glider rating. He replied that a rule of thumb is that a student’s age is equal to the number of flights it takes before soloing. Therefore, a 14-year-old could quite possibly solo after 14 hours of instructor flights.
Doing the math in my head, I quickly realized that, at my age, I probably couldn’t afford the training.
Sky Soaring has a well-done website with a gallery that includes a number of videos. One video in particular demonstrates winch-launch training. Single-engine pilots might be startled while watching the video when, on a short-final, the sailplane appears much too low to make the runway! As the sailplane settles safely, the realization sets in that just inches separate the center wheel from a glider pilot’s butt, as opposed to the several feet of main gear that keep powered pilots above a runway. https://youtu.be/VrEd5DK8R5E
The club currently has about 85 members, owns five sailplanes of various configurations, a C182A tow plane, and has one of the most active sailplane flight training programs in the Midwest.
Very special thanks to John Osborn for taking the time to answer my many questions and give me a tour of Sky Soaring’s grounds. If you have any interest in soaring, you would be hard pressed to find a more encouraging group of people. Check Sky Soaring’s website to learn more about this very active club. http://skysoaring.com/
Or, if you just feel like doing some exploring from behind the wheel of a car, head on out in search of Harmony!