Queen of the Waves: The Stemme S10-VT in Klaus Ohlmann’s Hangar

The Stemme S10-VT is the ultimate definition of freedom and high-performance aviation. While conventional gliders are strictly dependent on towplanes or ground crews, this autonomous, high-end touring glider breaks all system boundaries. It has been Klaus Ohlmann’s trusted weapon of choice for the most extreme atmospheric expeditions on Earth—including his pioneering flights over the peak of Mount Everest.

The Ingenious Metamorphosis
The centerpiece of the S10-VT is its invisible, revolutionary propulsion system. The heavy turbocharged engine is mounted in the center of gravity directly behind the pilots, ensuring perfect trim at all times. Power is transmitted to the nose via a carbon-fiber driveshaft. Upon starting the engine, the nose cone elegantly slides forward, and the propeller blades deploy through centrifugal force.

Once the engine is shut down in the mountain wave, the propeller folds back completely, the nose seals flush, and the aircraft instantly transforms into a pure, drag-free racing glider with a breathtaking 1:50 glide ratio.

Technical Specifications
Directly from the flight manual—the hard facts for your international audience:

Geometry & Weights
Wingspan: 23.00 m (foldable to 11.40 m for easy hangar parking)
Length: 8.42 m
Wing Area: 18.70 m²
Aspect Ratio: 28.3
Cockpit Layout: Side-by-Side (2 seats)
Empty Weight: approx. 645 kg
Maximum Takeoff Weight (MTOW): 850 kg

Engine & Motoring Performance
Engine: Rotax 914 F2/S1 (4-cylinder turbocharged aircraft engine, liquid/air-cooled)
Takeoff Power: 115 HP (85 kW)
Cruising Speed (Powered): 230 – 259 km/h (140 kts)
Rate of Climb: approx. 4.1 m/s (800 ft/min)
Range (Powered Cruise): up to 1,730 km (with maximum fuel configuration)

Gliding Performance
Best Glide Ratio: 1 : 50* at 110 km/h (59 kts)
Minimum Sink Rate: 0.57 m/s at 78 km/h
Stall Speed (V_S): 78 km/h (42 kts)
Never Exceed Speed (V_{NE}): 270 km/h (146 kts)
G-Load Limits: +5.3 / -2.65 g

The Record Fact:
It was exactly this aircraft type that Klaus used to secure one of his legendary FAI world records, flying a free distance of *2,463 kilometers* along the Andes all the way to Tierra del Fuego. It remains the perfect symbiosis of ultimate range and pure soaring performance.