Electric propulsion pioneer MagniX is preparing to take delivery of a De Havilland Canada Dash 7 for modification to a hybrid-electric testbed under NASA’s Electrified Powertrain Flight Demonstration.

The project is the first for which MagniX will develop the entire propulsion system, from batteries to motors.

The retired 50-seat turboprop is being provided by project partner Air Tindi, a Canadian regional carrier based in Yellowknife, Northern Territories. The aircraft is undergoing a C-check and corrosion inspection to restore its certificate of airworthiness before being delivered to MagniX late this month or in early August. 

Everett, Washington-based MagniX was awarded the $75 million NASA Electrified Powertrain Flight Demonstration (EPFD) contract in September 2021. Partners are Air Tindi and aircraft modification and flight testing specialist AeroTEC, based at Moses Lake in Washington. A second EPFD contract was awarded to GE Aerospace, to modify a Saab 340.

While MagniX has flown electric engines on several different test aircraft, the NASA program plays a key role in the startup’s plan to type certify electric propulsion systems as early as 2025. “The demonstrator is on the path to certification,” says Ben Loxton, MagniX vice president of the EPFD program.

MagniX’s contract is to develop a parallel-hybrid propulsion architecture and demonstrate how an aircraft can be hybridized in stages. In the fixed-price first phase of the contract, one of the Dash 7’s four Pratt & Whitney PT6A turboprops will be replaced by a 650-kW MagniX mangi650 electric engine. A second PT6A will be replaced in the cost-shared second phase.

“NASA’s goal is to accelerate the entry into the market of electrified powertrains starting with commuter-size aircraft, so 50-100-passenger regional turboprops,” Loxton says. “MagniX’s approach is to take a four-engine turboprop from the 1970s and replace two of those engines with our electric powertrains. The goal of EPFD is to demonstrate megawatt-class electrified powertrains and megawatt-class requires two engines to be replaced.

“Through doing that, you can play with the power hybridization between the turbines and the electrics. Depending on the mission, you get more or less fuel saving,” he says. “On a 200-mi. mission, which is a typical regional mission in the U.S., you can achieve up to a 50% fuel saving with this hybridized aircraft.” 

On shorter missions, more battery power can be used and fuel savings will be significantly more than 50%. “And you still retain the ability to fly to the full range of the aircraft, up to 500 mi. or so, but the percentage gain comes down to 20-30% fuel savings,” Loxton says.

“Parallel hybrid allows you to make meaningful fuel savings with today’s technology and then, as battery technology improves over the years and decades, the batteries can be replaced on the same aircraft and you can realize more fuel savings because of the higher energy in the battery,” he says.

NASA’s goal is to accelerate maturation of the technology and identify gaps slowing certification of electrified propulsion for Part 25. “The parallel hybrid architecture needs to go through certification, so Part 25 in the case of the Dash 7. The electric powertrain needs to be certified to Part 33 to go on that platform and the battery certified to some yet-to-be-determined standard,” Loxton says.

An electric propulsion unit has not yet been certified under Part 33 for aircraft engines, but the first special conditions for type certification were issued by the FAA for the magni650 in September 2021. “That being a performance-based compliance document, we have to demonstrate that the system meets the intent of those regulations,” he says.

“Within that there are some challenges, and NASA is able to bring a lot to the table to help us identify those and work with the regulators and industry standards bodies to develop the standards by which the aircraft and equipment will get certified,” he says.

MagniX is beginning certification testing with the final conforming version of the magni650 and, in partnership with NASA, planning to conduct simulated altitude testing of the electric engine this year in the NASA Electric Aircraft Testbed in Sandusky, Ohio.

After taking delivery of the Dash 7, MagniX and its partners plan to conduct a baseline flight test to collect data on the aircraft’s performance premodification. “We’re coming up to the preliminary design review at the end of this year and then next year it’s going through the critical design phase and modification work for a flight in 2025 with the electric powertrain,” Loxton says.

The electric engine will be installed in a new outboard nacelle. The Dash 7 is powered by a unique and older version of the PT6, the -50, while the magni650 is designed to replace the modern PT6, so there is some re-engineering required, he says. The direct-drive Magni650 will power a new high-speed propeller, replacing the original low-rpm Dash 7 unit optimized for short takeoff.

NASA’s EPFD is the first program for which MagniX is also responsible for developing the energy storage and power distribution systems. For ease of installation, the battery packs will be fitted in the passenger cabin of the demonstrator. Power distribution is at 800 volts, Loxton says.

In MagniX’s parallel hybrid architecture, the electric engines are independent of the turbines and of each other, he says, with a separate battery pack for reach electric powertrain. In a production design, management of hybridization is expected to be automated but will be manual in the demonstrator.

While AeroTEC is responsible for aircraft modification and flight test operation, Air Tindi will have a continuing role on the project. “They’re going to be involved in continuing maintenance and support for the aircraft. And they provide really interesting insight from an operator’s perspective,” he says.

“As engineers we can sit around a table and think about how these things might be operated. As [an] operator, how you might do that is an interesting part of EPFD,” Loxton says. “It’s producing a product that can enter service and is not just hypothetical. It’s talking to the maintenance crews, the pilots, the real-world operators and making this practical in the field.”