Catching up on the State of eCTOL Aircraft

EF Global VTOL

21 Mar 2023



VoltAero's Cassio 1

Ampaire flew its dual-powered Electric EEL 296 nm (548 km), a record for a commercially relevant eCTOL aircraft, in 2.5 hours. (Ampaire photo). (VoltAero photo)

Electric conventional takeoff and landing (eCTOL) aircraft are anything but conventional, but include many of the same challenges as electric vertical takeoff and landing (eVTOL) aircraft, most especially, of course, with the power systems.

Despite a global pandemic, the pace of development of eCTOL is still largely on track. Ampaire has just demonstrated the longest flight on record of an electric-propulsion civil aircraft and VoltAero successfully tested its unique internal combustion engine (ICE) propulsion system, while electric propulsion company magniX continued flight testing its motors with a larger aircraft, this time an all-electric Cessna Caravan 208B.

Ampaire’s Longest Commercial Electric Aircraft Record
Continuing its strategy to retrofit current aircraft to combined electric and combustion powerplants, Ampaire is getting ready to test its converted Cessna 337 “Electric EEL” in Hawaii, where it will conduct flight trials with Mokulele Airlines.

Powered by a 310-hp (230-kW) Continental IO-550 engine located in the rear of the aircraft and a 130-kW electric motor in the nose, the electric EEL flew its longest nonstop flight from Los Angeles to San Francisco, California, on Oct. 8. Ampaire said it could be flying passengers in just a few years since it is only replacing one of the two engines on the otherwise conventional, certified aircraft. The company is now studying the conversion of the de Havilland Twin Otter to hybrid power, which it calls the Eco Otter SX. 

Ampaire dual-powered Electric EEL

VoltAero’s Cassio 1 made its first flight on Oct. 8, using a piston engine to generate electricity for all three propellers. (VoltAero photo)

VoltAero Tests Its Unique Powertrain in the Air
VoltAero has a unique take on the future of urban air mobility (UAM) and regional air mobility (RAM) needs. Its all-composite aircraft Cassio 1 (loosely based on the Cessna 337) replaces its single, forward propeller with two 60-kW Safran ENGINeUS 45 electric motors mounted on the wings. The rear pusher propeller is powered by three 60-kW EMRAX electric motors.

The Cassio I uses a highly retuned 402-hp (300-kW) modified Nissan V6 internal combustion engine to charge the battery and provide direct power to all three motors, including a connection to the rear propeller. The Cassio 1 has a unique, motorized nose gear that lets it taxi quietly late into the night. VoltAero founder and CEO Jean Botti (a former Airbus CTO) said the company tested the bio-engine on its maiden flight on March 10 at its Royan-Médis Aérodrome facility.

Universal Hydrogen - Closed Loop H2 Generation

Universal Hydrogen has partnered with magniX to develop hydrogen fuel cell-powered eCTOL conversion kits, with closed loop H2 generation. (VoltAero photo)

magniX Looks at Bigger eCTOL
In December 2019, electric motor company magniX converted a De Havilland Canada DHC-2 Beaver seaplane with Harbour Air in Vancouver, Canada. In May, magniX partnered with AeroTEC to fly an all-electric 11-seat Cessna Caravan 208B, the world’s heaviest eCTOL aircraft flown to date.

Now magniX has partnered with a new California start-up, Universal Hydrogen, which is developing a kit for the De Havilland Canada DHC-8. Universal Hydrogen will develop the hydrogen fuel cell conversion kit and magniX will provide the electric propulsion system for the 40-passenger regional aircraft. More than 1,200 Dash 8s have been sold around the world and the conversion kit could be applicable to the similar-sized ATR42.