Seventeen years after the retirement of the Concorde, a small fighter-like aircraft nearing completion in Colorado is set to blaze a trail toward development of the first purpose-built civil supersonic airliner of the 21st century.
Boom Supersonic’s XB-1 is a one-third-scale demonstrator for the Overture, a follow-on 75-seat airliner it aims to introduce into commercial service later this decade.
Although inspired by the Concorde, the XB-1 displays key technology differences that Boom believes will enable the Overture to operate economically and sustainably at Mach 2.2—targets out of reach when the pioneering Anglo-French airliner left the drawing board more than a half century ago.
The XB-1 shares some Concorde-like features, including a slender nose, elongated forward fuselage and graceful ogival delta wing. But unlike the Concorde, the wing is mounted on the upper fuselage and predominantly made of lightweight carbon-composite materials rather than special aluminum alloys.
The XB-1 is also a trijet, and its tail-mounted engine is fed by a dorsal inlet, marking another significant departure from the Concorde’s twin-podded quad-engine configuration.
Once complete, the aircraft will be officially unveiled later this summer before being prepared for system checks and ground tests—including initial slow-speed taxi trials—at Centennial.
Testing will be undertaken with Mojave-based Flight Research Inc. (FRI) a training, service and support company with which Boom announced a strategic partnership in January. FRI’s supersonic T-38 will provide pilot proficiency training and will also be used for chase support during XB-1 flight tests.
With a wingspan of 21 ft. and overall length of 61.5 ft., the XB-1’s proportions are similar to the slightly shorter Lockheed F-104 Starfighter and the longer Douglas X-3 Stiletto supersonic research aircraft of the 1950s. The aircraft’s slender, low-drag delta wing is designed for supercruise performance and at lower speeds will generate vortex lift to allow an acceptable angle of attack for landing and takeoff.
For the Overture design, which will be firmed up within 24 months, the engines will have variable–geometry inlets and be mounted farther outboard while, according to current renditions, the tail engine will feature a divided inlet with openings on either side of the aft fuselage.
The three XB-1 engines, which collectively generate 12,300 lb. thrust in afterburner, are housed in an aft-fuselage assembly made completely from heat-resistant titanium. Small movable horizontal tails are attached to the lower aft engine nacelles to provide pitch control. Boom confirms that the horizontal tail will not feature on the Overture, which will be designed with a chine and a larger, conventionally mounted delta wing. An elongated conical tail cone extends aft of the vertical fin to reduce afterbody drag, particularly during transonic flight.
Boom’s plans to work with California-based Prometheus Fuels on a carbon-neutral fuel received a boost in June when the startup received an investment from the venture-capital arm of carmaker BMW. Boom partnered with Prometheus in 2019 for the supply of fuel for the XB-1, which will be produced using a process in which CO2 is captured from the air and converted into a liquid fuel using renewable electricity.