Dayton Area Thermal Soarers, Dayton, Ohio, USA
- Dayton Area Thermal Soarers club information:
- activity: Aircraft
- number of members: 1
- located: Dayton, Ohio, USA
Radio Controlled Thermal Soaring
Model sailplanes are capable of unpowered flights that may last from a few minutes to over 2 hours depending upon weather conditions and the skill of the pilot.
The models utilize rising warm air "thermals" to gain altitude in much the same manner as do hawks and vultures. In fact, it is not uncommon to end up sharing a thermal with a passing hawk on a long flight.
The models flown range from relatively simple, inexpensive, built up spruce and balsa aircraft with basic rudder and elevator controls to high-tech carbon fiber/fiberglass/epoxy composite models with ailerons and flaps and "computer" radios which allow mixing of the various control surfaces. The models range in size from about 60-inch wingspan for hand launched sailplanes to spans of around 120 inches for unlimited class models.
Models are either hand launched, winch launched, or "high started" with a long piece of stretched-out surgical tubing hooked to several hundred feet of towline. A ring on the end of the winch line is attached to a hook on the underside of the model for launching.
The ring stays on the hook under launch tension, and then falls free when the line slackens at the end of the launch. A parachute is attached to the ring to allow the line to drift gently back to earth after the launch.
A typical launch gives the model 400-500 feet of altitude, which is good for up to about 7 minutes of flight time under no-lift conditions.
The pilot has this much time to seek out a thermal that will allow the model to gain altitude and extend the flight.
Model sailplanes provide an ideal way to get in to radio controlled modeling.
They can be inexpensive (the cheapest kits are under $30 and they do not require a motor and all of the support equipment needed to fuel and start it). They fly fairly slowly (giving the novice time to react), and they are designed to be fairly stable (so that they can be flown at great distances without loss of control). A good quality 4 channel radio system with servos, rechargeable batteries, and charger can be purchased for about $130.
There are also some entry-level radios that are considerably less expensive.
In the past year or so, a new type of model has evolved out of the California soaring scene. This can best be described as "models that bounce".
Several kits are now on the market aimed at the new flyer which are made of expanded polypropylene (epp) foam (which originated as a packing material). It is not uncommon to see one of these models crash straight into the ground from 50 feet and remain flyable.
The models are covered in strapping tape and packing tape, and are ideal for getting the new flyer past the initial stages of learning to control the model.
