Pratt & Whitney will supply geared turbofan (GTF) engines for the truss-braced-wing narrowbody aircraft demonstrator Boeing is developing under a NASA project.

Disclosed by RTX, the Connecticut engine maker’s parent, on 3 October, the company says subsidiary Collins Aerospace will also contribute to the aircraft, called X-66A, supplying nacelles and engine accessories.


X-66A with P&W GTF engines


Boeing has chosen P&W to supply GTF engines for the in-development X-66A truss-braced-wing demonstrator 

Boeing will modify an MD-90 aircraft with what it calls the Transonic Truss Braced Wing – a long, slender structure with a high aspect ratio, supported by a truss joined to the lower fuselage. First flight is targeted for 2028.

Media outlets have reported that P&W competitor CFM International will also supply its RISE open-rotor demonstrator engine to the X-66A programme.


It says the architecture could inform the design of an aircraft to replace the 737 Max in the 2030s.

“NASA’s Sustainable Flight Demonstrator is a leading example of how public-private partnerships can help foster the technological breakthroughs needed to deliver on the industry-wide goal of a more sustainable, net-zero emissions future,” says P&W senior vice-president of engineering and technology Geoff Hunt.

“We’ll work with Boeing to apply GTF engines to the X-66A and help demonstrate the potential of its pioneering truss-braced-wing design.”

NASA will invest $425 million in the programme over seven years, while Boeing and its partners will contribute the remainder of the funding, estimated at about $725 million.