Turbine engine maker Williams International has successfully completed a test flight of its FJ44-4 engine running on 100 percent sustainable aviation fuel (SAF). This followed extensive material compatibility and endurance ground testing that validated engine performance and reliability using SAF.
The FJ44-4, which powers the Pilatus PC-24 light jet, was mounted on a Citation CJ4 testbed for the 3.5-hour flight on March 29 at Williams’s flight operations center in Pontiac, Michigan. Chief test pilot Robert Lambert noted the flight over northern Michigan was “uneventful and the engine performed flawlessly.” The aircraft reached a cruise altitude of 45,000 feet.
According to the engine maker, the more than 6,500 FJ44/FJ33 engines in service have accumulated more than 15 million hours in operation, and this flight marked another step in its Blue Planet initiative aimed at significantly reducing business aviation’s environmental impact.
“We have shown that Williams engines can use 100 percent SAF to decarbonize business aviation,” said company president, chairman, and CEO Gregg Williams. “The next critical step is to accelerate the production of SAF to make it more widely available and affordable.”