Alpha Electro (prototype name WATTsUP)

The prototype WATTsUP was developed in partnership with Siemens AG, who provided the electric main propulsion components, and represents the next generation of Pipistrel’s electric aircraft. Every single element of aircraft has been refined to be lighter, more efficient and more reliable. The 85 kW electric motor only weighs 14kg and is more powerful than the popular Rotax 912 series, typically used on microlights and LSAs. The 17 kWh battery pack is dual-redundant and designed to be either quickly replaceable within minutes or charged in less than one hour, thanks to the next generation of Pipistrel’s Battery Management technology. The airframe uses proven features from hundreds of Pipistrel’s aircraft flying worldwide.

Frank Anton, Executive Vice President Traction Drives and the initiator of electric aircraft development at Large Drives, Siemens AG, says: “Siemens is developing electric drive systems with highest power-to-weight ratio for aircraft propulsion. Only with innovation we can solve the problems of rising fuel costs, rising passenger demand and rising environmental regulations. Innovations used in the WATTsUP will be instrumental in making aviation more sustainable in the long run. As electric drives are scalable, we can expect, that in the future also larger aircraft will use electric propulsion. The world is becoming electric, whether in the air, on land or at sea.”

Aircraft technical data  

Technical data
Motor electric motor
power 50 KW+ at 2200 rpm
PROPELLER Fixed pitch wooden 1800 mm (71 inch) diameter propeller with protected leading edge
wing span 34,4 ft (10,5 m)
length 21.33 ft (6.5 m)
height 6.07 ft (2.05 m)
wing area 96.6 sq.ft (9.51 m2)
rudder area 11.8 sq.ft (1.1 m2)
horizontal tail area 11.6 sq.ft (1.08 m2)
aspect ratio 11,3
positive flaps 0°, 15°, 25°
center of gravity 20% – 38% MAC
empty weight (without batteries) 553 lbs (251 kg)
empty weight (with batteries) 692 lbs (314 kg) *OR* 831 lbs (377 kg)
maximum total pilots weight 440 lbs (200 kg)
max take off weight (MTOW) 1212 lbs (550 kg)
weight of std battery system 277 lbs (126 kg)
PERFORMANCES DATA PUBLISHED FOR MTOW 1,212 lbs (550 kg) All speeds in Knots
stall with flaps 37 kts
stall without flaps 43 kts
cruising speed 85 kts
max. horizontal speed at sea level 105 kts
VNE 135 kts
max. speed with flaps down 70 kts
maneouvring speed 86 kts
best climb speed 75 kts
max climb rate 1,220 fpm
best glide ratio speed 64 kts
best glide 15:1
take off run MTOW 459 feet (140 m)
take off over 50′ obstacle MTOW 968 feet (295 m)
service ceiling 16,000 feet
45°-45° roll time 2.6 sec
endurance 1 hour (PLUS 30 min reserve)
cruise range distance 81 NM (150 km)
max load factor permitted (x1,8) +4g -2g
design safety factors & tested minimum 1.875

Pipistrel reserves the right to revise the above data whenever occasioned by product improvement, government/authority regulations or other good cause.
The design basis follow the strictest EASA CS-22, CS-VLA and CS-23 (sections), as well as rules applicable to ultralight/microlight aircraft (LTF-UL 2003, etc.) and ASTM-LSA standards.
Ultralight/Microlight certification basis varies from country to country, therefore the actual certificated data may be different from stated above. Please check the certifications link.