elfin - freedom reinvented

The three-blade folding propeller is tailor-made for the requirements of the elfin electric motor glider. Retractable blades are its unique and proven feature, combining efficient propulsion, if needed, with zero drag in soaring mode. Our high-tech propeller generates outstanding performance in both worlds. When invisbly folded into the plane’s nose, the perfect aerodynamics and beauty of a high-performance glider aircraft are preserved.

Moving the nose cone for blade unfolding as well as the activation and operation of the powered flight is controlled via a single lever. This minimizes the procedure and risk of failure for pilots who can remain fully focused on flying the aircraft. Switching between gliding and powered mode just takes seconds with no noticeable change of drag or center of gravity shift happening.

The three-blade propeller is optimised for electric propulsion. Its individual blades unfold by centrifugal force while especially  designed mechatronics ensure smooth in and out movements with minimal impact on parts and structure. Our long high-tech materials experience opted for a mainly carbon-made propeller boasting highest standards of safety and longevity at minimal maintenance.

The change from a two-blade folding propeller, patented by Reiner Stemme for the S10 series, to a new three-blade design provides elfin with clear advantages. Its propeller is not only optimized for electric propulsion but works now at significantly lower noise levels with slower revolution still delivering sufficient thrust. As the aircraft’s nose cone has received a nearly rounded shape, vibration levels have been lowered further. The propulsion system is perfectly positioned at the front tip of the aircraft where it usually unfolds maximum thrust efficiency on single engine aircraft.

Performance data of elfin’s propulsion system you might like to know: Take-off roll on unpaved and dry RWY is 250m (820 ft). The plane’s climb rate is 3 m/s (590 ft/min) and its typical cruise speed is up to 185 km/h (100 kts TAS). 

Electric flying is friendly to the environment, powerful and reliable. You will be amazed about the low noise levels of elfin’s electric motor – in- and outside of the cockpit. It seems like complete silence compared to conventional combustion plane engines. And low vibration levels increase comfort and joy of flying further to a new and pleasurable experience of powered flight.

The elfin is powered by an EMRAX 268 electric motor, made by the eponymous Slovenian technology provider with ample development and application experience in the fields of electric propulsion. Applying a powerful 65 kW (88 hp) to the unique elfin folding propeller, the EMRAX 268 ensures a climb rate of at least 3 m/s (590 ft/min).

At a weight of only 20 kg the electric motor is compact enough to be installed right at the aircraft’s front end without shifting the center of gravity or causing undesirable drag. The entire system design is optimised and the engine directly flanged to the propeller. No gearbox is needed, saving weight and doing away with a part that creates frequently substantial maintenance cost while also showing significant failure rates.

The extremely fast availability of a full power level is a also remarkable safety feature of elfin’s electric motor. It allows, next to efficient cruising flight, also for a quick initiation of go-arounds. Needless to say that elfin’s combination of electric motor with a retractable propeller is the optimal solution to delete drag and center of gravity shifts when the pilot switches from soaring to powered flight and vice versa.

This is performance data of the elfin propulsion system you might like to know: Take-off roll on unpaved and dry RWY is 250m (820 ft). The plane’s climb rate is 3 m/s (590 ft/min) and its typical cruise speed is up to 185 km/h (100 kts TAS). 

Side-by-side cockpits are rare in the glider aircraft world. But it gives so much more joy and pleasure when amazing flight experiences can be shared. Cosy and comfortable, the elfin cockpit’s huge canopy guarantees fantastic panoramic views that are unrestricted by wings.

To protect elfin pilots as far as possible, we use state-of-the-art design, technologies and materials to make the plane’s cockpit as crash-safe as possible.

A low-level sill gives both pilots easy access to the cockpit. This is especially convenient when you prefer to fly with your own parachute – allthough the elfin integral ballistic rescue system makes it unnecessary.

We want you to come back to the ground safely – even in the worst case. Hence elfin comes with a ballistic rescue system as a standard feature bringing the whole plane, if necessary, smoothly down to earth suspended from a large, single parachute. The system is easy to trigger while also being sufficiently protected against unintentional use. Still all passengers, even without flying experience, can release it in a split seconds if necessary.

Even at lower altitudes the ballistic rescue system is able to save pilot lives by bringing them down safely. We chose BRS Aerospace as partner for the elfin rescue parachute system. These systems are the most tested and they have rescued already hundreds of pilot lives worldwide.

The battery technology enjoyed big advances over the last years so that aviation can now benefit from electric propulsion systems safely. Longevity has strongly increased, keeping their performance outstanding for a very high number of loading cycles while overheating is no longer a threat, as long as adequate battery types are chosen.

Depending on preferences such as flight range you can scale elfin’s onboard electric power system by assembling more or less battery units.

Does battery-stored electric power limit your range, or are you flying in a region with only patchy charging infrastructure? Our Range Extender, a small combustion engine, is the solution flying the extra mile. It propels you with up to 90 liter of fuel from onboard tanks and recharges the batteries via an onboard generator.

Are you going on a longer trip and can’t wait for the batteries to charge? Refuelling the Range Extender is possible at nearly every airfield, increasing your independence even further.

The retractable undercarriage and steerable tail wheel ensure full independence in operation. Taxiing under power is safe and easy. Ground handling and hangaring are eased by unlocking the tail wheel to a 360° swivel.

Both main landing gear and tail wheel are retractable to ensure an aerodynamically smooth shape for the best performance in gliding as well as electric-powered flight.

Both wings feature integrated fuel tanks with a capacity of 45 litres each. They enable the elfin to go, with a range extender, on long-range flights of up to 1.100 km / 600 NM. They can compensate either occasional lacks of fast battery refilling options or complement the limited range of pure electric-powered flight.

Water tanks in both wings can each take up 50 kg of ballast water to increase wing loading and speed up the aircraft in soaring mode.

Flaperons running along the whole wingspan allow for the perfect adjustment of the airfoil to flown speeds. This improves significantly the performance and speed along with providing even a noticeably smoother flight feel at higher speeds.

A common problem: A 65.7 ft / 20 m wingspan is not easy to hangar or it is even impossible to get hangar space for that size. No problem for elfin: A simple one-man operation reduces the wingspan to 33 ft / 10 m. You can even taxi the aircraft in this configuration, if you have not enough space available on your airfield.

elfin provides a unique solution: Get the wing over the fuselage via a turntable that rotates the folded wing lengthwise – for a hangar space of only 11.5 m x 1.5 m (37.9 ft x 5.0 ft).

The retractable undercarriage and steerable tail wheel ensure full independence in operation. Taxiing under power is safe and easy. Ground handling and hangaring are eased by unlocking the tail wheel to a 360° swivel.

The main landing gear and tail wheel are retractable to ensure an aerodynamically smooth shape for the best performance in both – gliding and electric-powered flight.