Saudi Arabia’s Neom Investment Fund (NIF), the financing group associated with the Saudi smart city development, has confirmed finalization of a strategic investment in high-speed airliner developer Boom Supersonic.

Although no details of the NIF investment have been disclosed, Boom says the Saudi group forms part of a recently closed financing round which brings the company’s total funding to more than $700 million. Boom expects the Middle East, and Saudi Arabia in particular, to be a key player in the supersonic market for which it is developing the Mach 1.7 Overture airliner.

The NIF supports several advanced transport projects and concepts which could feature in future infrastructure for the $500 billion Neom Red Sea project, a broad initiative which has been launched as part of Saudi Arabia’s Vision 2030 project designed to diversify its economy away from oil. Under Neom, Saudi planners are building a series of huge resorts, industrial complexes and airports on the country’s northwest coast.

In October NIF also announced it had made the single largest investment in U.S. electric seaglider developer Regent’s $60 million Series A round. Regent will establish a Middle East R&D and training hub at the smart city development and conduct on-site testing to prepare for passenger and freight transport operations along 290 mi. of Red Sea coastline starting by mid-decade.

Boom, meanwhile, says it has successfully completed its conceptual design review of the Symphony propulsion system in advance of the first hardware rig tests planned for 2024. 

The new centerline engine is under development by a Boom-led industry team including Kratos subsidiary Florida Turbine Technologies, GE Additive and StandardAero. The two-spool, 35,000-lb.-thrust medium-bypass turbofan engine is planned to be equipped with a single-stage 72-in.-dia. fan and be optimized for prolonged supersonic operation with an air-cooled, single-stage, high-pressure turbine and a three-stage low-pressure turbine.

The Symphony’s compressor will consist of a six-stage high-pressure unit and a three-stage low-pressure section. The supersonic inlet, diffuser and exhaust design is crafted to meet Chapter 14 noise levels.

Boom’s XB-1 sub-scale demonstrator is meanwhile poised to make its first flight at Mojave, California, following a recently completed flight-readiness review. The aircraft has conducted runway runs up to 90 kt. as well as ground vibration-mode testing, fuel system-integrated testing and engine-operability testing.