A whole new source of energy for aviation is on the horizon, and the first rays of light from this “green” energy source have emerged from an old power source… that being electricity. Sure, electricity is a key ingredient in most aircraft now, be it in avionics, in-flight entertainment, and even in flight controls. But until recently, electricity for main powerplants for aircraft haven’t been perfected enough for mass production. That’s changing at a rapid pace, and with the vision of more earth-friendly and carbon neutral flight operations gaining headlines, there’s plenty of optimism for electricity to assist in attaining meaningful reductions in aircraft powerplant emissions. Let’s look at a few aircraft which, in the year 2022, were highlights in this quest for cleaner emissions.
Ampaire, a Los Angeles-based company “was formed in 2016 with a mission to become the world’s most-trusted developer of practical, compelling electric aircraft. The company is upgrading existing passenger aircraft to hybrid electric power –the quickest, most capital efficient approach to making commercial electric air travel a reality with available technology” according to their recent press releases. Their battery-powered electric motors are teamed with existing powerplants in the Electric EEL aircraft, which are testbeds for current and future use of electric power. At the 2022 EAA AirVenture in Oshkosh, Wisconsin, the second Electric EEL was flight-displayed by noted test pilot Elliot Seguin during Tuesday’s Innovations flying showcase. Just getting to Oshkosh from California, it broke an endurance record for aircraft in its class!
The EEL, which is a modified Cessna 337 Skymaster, carries an electric motor in the nose, and its conventional Continental engine in the rear. In this hybrid scheme, the electric motor is used during parts of the flight when an abundance of energy is needed, namely during climb and maneuvering. The electric motor uses batteries carried in the belly pods of the aircraft.
After landing, the EEL utilized only the electric engine to taxi back to parking, another way to conserve fuel and reduce emissions.
Test flights using the Electric EEL Skymaster were operated in Hawaii for inter-island flights that Mokulele Airlines envisions in the future. In short, the island-hopping airline plans to be the launch customer for a hybrid conventional and electrified version of the Cessna C-208 Caravan using an electric powerplant as well as the Pratt and Whitney Canada PT-6A turboprop. In tests, a -30 to -40 minute charge while on the ground was sufficient for its next leg of flight. Many segments of Mokulele’s schedule are flights under an hour, and the hybrid combination is forecast to save the airline between a quarter and a third of their fuel expenses per flight. Thus far during the flight test campaign, neither extreme heat nor cold conditions didn’t produce any issues with battery operation.
The next step in Ampaire’s upgraded fleet is the Eco Caravan, a nine – passenger hybrid airliner (the conventional Caravan is the staple aircraft in the Mokulele fleet). The Eco Caravan will see a -50 to -70 percent reduction of fuel use and emissions during most of the airline’s flight operations according to Ampaire CEO Kevin Noertker. The Eco Caravan prototype first flew from a California airport on November 18th of this year, completing a thirty-three minute flight. The aircraft will be able to recharge its batteries while in flight, and will be certified under a Supplemental certificate, since the Cessna Caravan is already fully certified. A concept for the future includes a 4-engined electrified Twin Otter aircraft too.
A fully-electric powered Light Sport Aircraft nearing production is the Pipistrel Alpha Electro. The aircraft is still under the Experimental banner, although it is going through the FAA certification process. It is roughly similar to the European-certified Velis Electro trainer, but is going to be a bit lighter and equipped with some different flight systems. Endurance is envisioned to be sixty minutes, plus a thirty-minute reserve. At the recent Simsbury, Connecticut Fly-In, Learn2Fly, LLC personnel noted that a one-hour flight lesson is a normal length of time for initial flight training. The company notes in its literature that by using an electric motor while in the traffic pattern, soaring fuel costs can be avoided and the cost of flight training reduced. It also notes that their electric motor is more powerful than the popular Rotax 912 series of engines too.
The two-seat LSA trainer was roomy and carried its own charging apparatus on the right side of the airframe. Electric motors take up much less room and weight, compared to their combustion-powered ancestors, but battery packs add to the overall weight equation. But, with no liquid fuel aboard, it allows for making it useful in the LSA realm of being under 1,320 pounds gross weight.
Pipistrel is based in Slovenia, and now owned by Textron eAviation. Begun in 1989, the name means “bat” after the flying mammal. From hang gliders to today’s light general aviation designs, some 1,300 aircraft have been produced by the company.
Electric power for aircraft has already shown that savings are realized from decreased fuel use, and cleaner emissions operations meet goals outlined in future regulations. Ampaire and Pipistrel are flying aircraft now, in response to the changing times. What used to be something beyond the horizon has now risen and is a reality in an ever-changing world of efficiency and “green” operations.
