US aerostructures firm Spirit AeroSystems is to build the forward fuselage of the Aerion AS2 supersonic business jet, in return for additional investment in the programme.

Aerion says it has reached a memorandum of agreement to enhance Spirit’s role, after the two sides started co-operating on the AS2 last year with forward fuselage design work.

Sprit will build up to 36 fuselage assemblies annually once production of the aircraft – set to commence in 2023 – reaches full rates.

The company’s technical specialist capabilities have “significantly advanced” evolution of the design, says Aerion, and Spirit has become a “core enabler” of the programme.

Designed to break the sound barrier without the need for an afterburner, and powered by synthetic fuel, the AS2 is intended to travel at 870kt.

The AS2 will be assembled at Aerion’s headquarters in Melbourne, Florida.

“Through our collaboration with Aerion, we have contributed innovative and cost-effective design solutions to help make the AS2 a reality,” says Spirit chief Tom Gentile.

Details of Spirit’s investment in the programme have not been disclosed.

But Gentile says the company will bring both manufacturing and design capabilities to the “revolutionary” aircraft programme.