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Boom Technologies expects to start subsonic flight tests of its XB-1 supersonic demonstrator in late 2017. The engineering design was unveiled at the company’s Centennial airport facility in Denver, Colorado, on November 15.

Dubbed “Baby Boom,” the delta wing aircraft is a one-third scale demonstrator for a small supersonic airliner which Boom aims to certificate for commercial service by 2023. The XB-1 is 68 ft. long and powered by three 3,500 lb. thrust, non-afterburning General Electric J85-21 engines which are configured with specially developed variable geometry inlets and exhaust systems.

Designed to operate at Mach 2.2, and with a range of more than 1,000 nm, the 17 ft. span XB-1 is intended to pave the way for the follow-on development of a full-scale supersonic trijet transport seating 45 passengers in standard configuration, and up to 55 seats in a higher-density layout.

Constructed primarily of lightweight composites, the XB-1 is configured with a two-crew cockpit, a chined forebody and swept trailing edges. The XB-1 has a maximum take-off weight of 13,500 lb.

The Boom concept is targeting affordable supersonic travel by using a collection of structures, aerodynamic and propulsion technology that was not available when the Anglo-French Concorde, the world’s first operationally successful supersonic airliner, was developed in the 1960s.

While the engineering design will be used to check equipment and systems layout and installation, the “flight-ready airframe is under construction now and will fly in late 2017,” says Boom. Following the expansion of the subsonic flight envelope over Colorado, supersonic flight tests will take place in restricted airspace near Edwards AFB, California, likely beginning in 2018.

Testing will be undertaken in partnership with The Spaceship Company (TSC), the Mojave-based manufacturing arm of Virgin Galactic which has taken options on the first 10 passenger-carrying aircraft. Virgin founder Richard Branson says the decision to work with Boom was “an easy one.” TSC, will “provide engineering and manufacturing services, along with flight test support and operations as part of our shared ambitions.”

Unlike a new generation of supersonic business jets and a NASA X-plane in development, the small airliner is neither a low-boom or lower Mach number design. Instead, the delta-winged Boom design is intended to rely on a 10% higher speed than that of Concorde to achieve high utilization and shorter sector times on 4,500 nm. routes, most of which will be flown over water. If successful, Boom’s airliner will fill a gap in the air transport industry that has been unfilled since British Airways retired the final Concorde in 2003.

The initial design of the full-scale aircraft has meanwhile settled with an overall length of 170 ft. and span of 60 ft. and differs in several key areas from the XB-1. The airliner variant will be configured with podded engines mounted close inboard and flush with the underside of the delta wing, and will feature a dedicated inlet for the tail-mounted engine with intakes mounted either side of the fuselage. The XB-1, on the other hand, has only two fighter-style rectangular supersonic inlets which are mounted below the wings alongside the fuselage. These inlets also feed the buried inlet for the tail engine via bifurcated ducts.

To augment the limited pitch stability of the XB-1’s very small slender delta wing, the demonstrator is also configured with sharply swept horizontal stabilizers, or strakes, which are mounted low on the engine nacelle, directly aft of the wing trailing edge.

The full-scale aircraft is designed with a larger area delta wing and, like Concorde, does not have canards or tail-mounted strakes or stabilizers.

The Silicon Valley-backed startup is supported by a range of entrepreneurs, venture capital firms and investment groups including 8VC, RRE Ventures, Lightbank and Y Combinator as well as angel investors such as computer scientist Paul Graham and Kyle Vogt, a robotics innovator whose self-driving car tech company was recently acquired by General Motors.A