Our drive system with internal combustion engine is trend-setting. In the process, we have systematically developed the familiar turbo concept, which is almost 30 years old, and completely revised the turbo drive. The second drive concept in addition to our very successful electric self-starter meets the following requirements:
- High climbing capacity, even at high altitudes
- safe starting in the air
- Significant improvement in reliability
- very low vibration level
- high comfort.
The turbo engine will be used in the Antares 18T and Antares 23T series.
A high climbing capacity of the turbo drive allows safe and comfortable flying even in high mountains. Sufficient power reserves for unfavorable ambient conditions were taken into account. High temperatures of 30° Celsius, high passes in the Alps, Andes or Rocky Mountains are no longer a safety risk. That’s why we opted for a very powerful engine and equipped our T variants with the proven 30 hp SOLO 2350C engine. This motor with gearbox made it possible to realize low speeds and high efficiency of the propeller. Its diameter is 1.36 m. The service ceiling is over 4,000 m.
Home with safety
Easy and safe starting in the air was a top priority during development. It clearly means an increase in safety for the pilot. For this purpose, we have developed a propeller with a large blade depth on the outside, which brings good efficiency both at start-up and in climb. Thus, our engine can already be started at comparatively low speeds (approx. 115 km/h). What every pilot actually knows is that the gliding polar curve of a glider deteriorates enormously with the engine extended. Already at 110 km/h, the inherent sink rate with the engine extended is 1.8 m/s and corresponds to a glide ratio of 1:18. At 130 km/h, a speed that many turbos need for startup, the inherent sink rate is already 2.8 m/s with a glide ratio of 1:12.9. There’s not much room for maneuver if things don’t work out right away. Unfortunately, this is why there have always been accidents with turbos. The loss of altitude during a crash is therefore decisive for the safety of the pilot.
Altitude loss for different run-up speeds.
For safety reasons, the required run-up speed should not exceed 120 km/h. Thus, the engine of the Antares 23T can be started safely at 110 km/h with the propeller specially designed with these aspects in mind.
Another critical moment occurs when the difference between the speed at which the engine starts and the speed at which the engine speed limiter kicks in and switches off the ignition is too small. If this range is too small, there is a risk that you will start flying so fast that when the engine does not start immediately, the ignition is immediately cut off again by the rev limiter. With our T variants, the difference between the approach speed and the overspeed is about 30km/h, a range that even a less experienced pilot can safely maintain. The problem can be avoided completely if the motorglider is equipped with a throttle and the speed limiter can be omitted. We offer this as an option. Finally, starting the engine is even safer with an electric starter, which we also offer as an option.
Simplest operation with safety
The highest possible safety of the overall system was also our most important premise for the T variants. As with our self-launching Antares 20E model, the pilot is relieved as much as possible when operating the engine. The engine is retracted and extended in the air largely automatically, along the lines of our electric motor glider. The short extension time of the power unit of about 10 seconds means very little loss of altitude until startup.
Comfort and performance in powered flight
A very low vibration level of the turbo drive system means direct relief for the pilot. The stress level of the pilot in powered flight with our T variants is much lower than with “normal” turbo engines and communication via radio is possible without any problems. The most important effect of the very low vibrations, however, is the high fatigue strength and thus reliability and low maintenance of the entire system. This is achieved by a completely redesigned and very rigid engine mount and a special damping engine suspension. The design of the gearbox also helps to dampen vibrations. The display of the cylinder head temperature (optional) in conjunction with the throttle cable, which is also optional, enables the powerful engine to always be operated in the optimum regime.
A large 16.2-liter fuselage tank provides good range and eliminates the need for flat tanks, which would have to be drained for transport in a trailer on the road.