Pipistrel WATTsUP Electric Trainer Aircraft

WATTsUP is a two-seat, fully-electric aircraft. Credit: Pipistrel.

The maiden flight of WATTsUP aircraft was completed in August 2014. Credit: Pipistrel.

The aircraft features a UV-protected, scratch-resistant Lexan windshield. Credit: Pipistrel.

The electric engine of the aircraft was developed by Siemens. Credit: Pipistrel.

The WATTsUP aircraft has a cruising speed of 85k. Credit: Pipistrel.

The WATTsUP aircraft is mainly offered to flight schools and the training market. Credit: Pipistrel.

The WATTsUP aircraft is expected to enter service in 2015. Credit: Pipistrel.

WATTsUP is a two-seat electric trainer aircraft developed by Slovenian light aircraft manufacturer Pipistrel. The aircraft is intended to meet the needs of flight schools.

The WATTsUP aircraft made its first flight in August 2014 and was displayed to the public at the Salon de Blois air show held in France, in the same month. It is expected to enter service in 2015.

WATTsUP aircraft design and features

The WATTsUP trainer is based on Pipistrel’s proven Alpha trainer aircraft. The new aircraft is designed to meet micro light and ASTM LSA criteria, and features similar airframe used for other aircraft manufactured by Pipistrel. The cabin houses two seats in side-by-side configuration.

The electric-operation of the WATTsUP aircraft offers fuel economy, low maintenance costs, and quiet flight. The efficient traffic patterns adopted by the aircraft save about 13% of the energy during each approach. The aircraft is also optimised for achieving take-offs from short distances and short-field landings.

The fixed landing gear includes two main units and a steerable nose wheel unit. The wings and tail feature tie-down points. The exterior of the aircraft is coated with acrylic paint finish.

Dimensions of the aircraft include length of 6.5m (21.3ft), height of 2.05m (6.07ft), wingspan of 10.5m (34.4ft), wing area of 9.51m² (96.6ft²), rudder area of 1.1m² (11.8ft²), and horizontal tail area of 1.08m² (11.6ft²).

Cockpit and avionics

The cockpit is fitted with a UV protected, scratch resistant Lexan windshield. The avionics system includes dual control stick, dual rudder pedals and in-flight adjustable pedals for both pilot and co-pilot.

The cockpit also includes a big instrument panel, including GPS Garmin Aera 500 + AirGizmoRadio Garmin GTR 200 with aerial, and two headsets HD-1000 with built-in intercom. An air speed analogue and digital indicator and a three-point door locking system are also fitted.

Engine and performance of WATTsUP trainer aircraft

The aircraft is powered by an electric water-cooled engine developed by Siemens. The engine develops 50kW (67hp) of power at 2,200rpm. It weighs 14kg and receives power from a quickly replaceable, dual-redundant 17kWh battery pack.

The battery pack can be rapidly charged within one hour using Pipistrel’s next-generation battery management system. The engine drives a wooden 1,800mm (71in) diameter fixed pitch propeller with protected leading edge.

The aircraft has a cruising speed of 85k and maximum horizontal speed of 105k at sea level. It attains a maximum speed of 70k with flaps down and a manoeuvring speed of 86k. It can fly at an altitude of 16,000ft and reach a cruise range distance of 150km (81nm). It has a maximum climb rate of 1,220ft/m, best glide ratio of 15:1 and best glide speed of 64k. The endurance of WATTsUP aircraft is one hour plus a 30 minute reserve.

The aircraft has an empty weight of 251kg (5,53lb) without batteries, and 314kg (6,92lb) with batteries. It has a takeoff weight of 550kg (1,212lb) of which the maximum total weight allocated for pilots is 200kg (440lb). The weight of the standard battery system is 126kg (277lb).