LE BOURGET—RTX company Pratt & Whitney has appointed modification specialist AeroTEC to convert a De Havilland Canada Dash 8-100 turboprop into its long-planned Hybrid-Electric Propulsion (HEP) flight demonstrator.
The modified aircraft, which was originally targeted to start flight tests in 2024, will incorporate a 2-megawatt parallel hybrid-electric powertrain system in place of one of the Dash 8’s two Pratt & Whitney Canada PW120-class turboprops. In addition to a 1-megawatt thermal engine, the system will also include a 1-megawatt, 1-kilovolt electric drive from sister RTX company Collins Aerospace and a battery system supplied by Swiss startup H55.
Conversion work will take place at AeroTEC’s Moses Lake, Washington, facility, where the company has amassed experience on several previous and ongoing hybrid and electric power modification programs. AeroTEC is currently modifying a MagniX-owned Dash 7 for NASA’s electrified powertrain flight demonstrator program, and a Cessna Caravan for Surf Air Mobility’s hybrid and all-electric Caravan project. The company previously also modified a Dash 8-300 into a hydrogen-powered demonstrator for now-defunct Universal Hydrogen. It also supported ground and flight tests of Eviation’s all-electric Alice aircraft and completed the initial conversion of MagniX’s battery-electric Cessna eCaravan.
Efforts to develop the powertrain have taken longer than expected. But Michael Winter, chief scientist at Pratt & Whitney parent company RTX, says the company is "doing this to learn. We want to do it right, and we want to do it carefully. We want to build these building blocks and put them together in ways that we understand how to safely and reliably certify it, to bring it into the fleet.”
Speaking at the
Paris Air Show, Winter added that “our partnership with AeroTEC will actually be the unlock that lets us really bridge that. If we were to do a flight demonstrator with, say, a prime airframer looking to the future, then there might be opportunities to work directly with them to do the integration. But we don’t have that luxury this time, and so AeroTEC is a wonderful partnership that allows us to bring that forward and to burn down those barriers and unlock getting to that flight test.”
Pratt’s move to contract with AeroTEC follows a recent successful ground test of the hybrid propulsion system at full power for a simulated full mission. The company
previously reported running the system to full power before the
Farnborough Airshow in 2024, but the latest test exercised the system for a longer period.
“We ran the entire system up to the full required power for the full mission, including the takeoff, as well as the recharge cycle on the batteries within the mission profile. That achieved more than 1,800 shaft horsepower, and we did this with a combination of drawing the power from the batteries as well as from the thermal engine. That’s actually a challenge for the batteries, because typically [the] batteries are designed for reducing the possibility of thermal runaway. That tends to limit how fast you can pull the current out and how fast you can put it back in. So we’re working closely with H55, which we are partnered with through RTX ventures, and we’ve achieved the full cycle,” Winter says.
