How It's Made - Gliders

[silver-eagle]

On Science channel at 2AM Tuesday morning. The glider built is a Schempp-Hirth Flugzeugbau Motoglider. How were things made before carbon fibre? What kind of engine do they put in a motoglider and what is the takeoff speed? This one looked like it folded into the fuselage. Gas or electric?
Once launched, do most shutdown the engine and just glide?

 

[weilke]

On Science channel at 2AM Tuesday morning. The glider built is a Schempp-Hirth Flugzeugbau Motoglider. How were things made before carbon fibre? What kind of engine do they put in a motoglider and what is the takeoff speed? This one looked like it folded into the fuselage. Gas or electric?
Once launched, do most shutdown the engine and just glide?

Before carbon fiber, they used glass fiber. Quite a bit heavier and flexes more.

Before glass fiber, they used wood, wood+fabric, tube+fabric or flush-riveted aluminum.

Motorgliders come in three flavors:
- Touring motorgliders, basically 2 seat powered aircraft like the HK Super Dimona.
- self launch gliders. Basically a glider with a fold-out engine that has enough power to accelerate the plane, take off and climb.
- 'limp home aid' type gliders. A small 24hp engine that can be used to buzz home if the thermals die off before you get home. They get launched in aero-tow or winch launch and the engine is only for contingencies.

Pretty much all of them use gasoline engines. Some of the fold-out engines are 2-stroke SOLO engines, others have 4-stroke and wankel engines. The touring motorgliders either have Rotax 4-cylinder engines or various conversions of VW industrial engines. There are some experimental designs using electrical or jet engines.