Williams gains approvals for latest FJ44 engine variant

Williams International has received type and production certification from US and European regulators for the latest variant of its FJ44-4 engine, which powers the in-development Pilatus PC-24 superlight business jet.

Gregg Williams, president and chief executive of the Michigan, USA-based company says the FJ44-4A-QPM – which stands for quiet power mode – is Williams's first engine model to be certificated as a complete integrated module.

“The turbofan includes a number of elements that have traditionally been designed and provided to the airframe OEM’s by other suppliers," he says. "These include our advanced, in-house manufactured, drag-reducing, heated inlet, our 'Exact' passive thrust vectoring exhaust nozzle, which provides significant performance benefits, and our proprietary QPM system."

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Pilatus Aircraft

This feature allows one of the FJ44 engines to act as an quiet auxiliary power unit while on the ground to enable air conditioning and electrical power to be provided. The QPM eliminates the need for what Williams describes as "a traditional, separate, expensive and heavy APU".

The -4A-QPM is also Williams's first engine model to be approved with its in-house designed and manufactured health-monitoring FADEC system.

Williams now plans to certificate and incorporate the FADEC on all models in its FJ33 and FJ44 engine families. The line-up covers the 1,000-4,000lb-thrust (4.45-17.8kN) range and powers a number of business aircraft including the Cirrus Vision SF50 personal jet and the Cessna Citation CJ4 light-twin.

Pilatus, meanwhile, is accelerating production of the PC-24 in preparation for its certification and service entry in the fourth quarter. The three test aircraft have accumulated more than 1,700h of flight testing since the maiden prototype made its debut sortie in 2015.

The Swiss company has sold 84 units, and plans to re-open the orderbook later this year in response to high demand for the seven-seat type.