Boom Supersonic’s successful second test flight of its XB-1 demonstrator on 26 August positions the company to accelerate the pace of the flight-test programme, with a third flight potentially coming next month.
“This was a red-letter flight,” Boom chief executive Blake Scholl says on 26 August shortly after the company completed XB-1’s second sortie, a 15min flight from Mojave Air & Space Port in the California desert.
The second flight comes five months after XB-1 lifted off for the first time, on 22 March, also from Mojave. Based on an initial review of the second flight, Scholl expects much less time will elapse between the second and third XB-1 flights.
“I’d be surprised if it took more than a month,” he says. “We are looking forward to leaning into the rest of the flight-test campaign.”
Boom is using the triple GE Aerospace J85-15-powered XB-1 test jet to inform its design of a conceptual passenger jet called Overture. It says Overture will carry 64-80 passengers and fly at Mach 1.7.
The company faces a long road to make Overture a reality but aims to have the jet in service by the end of this decade.
Notably, XB-1’s 26 August sortie allowed Boom to evaluate a new “roll-stability augmentation system” that engineers gave the aircraft following the first flight.
The system worked as designed, says Scholl, who posted video of the flight to X.
“Through the entire flight envelope we had good handling qualities,” he adds. “We have resolved the one issue we had from Flight One, with handling quality. We have a fix that is working well.”
Scholl had told FlightGlobal in July that his team was giving XB-1 the additional flight-control technology after finding the aircraft, during its first flight, to be “twitchy in the roll axis”. XB-1 also has pitch and yaw augmentation systems.
During the 26 August flight, Boom’s test pilot flew XB-1 to 10,400ft and hit a top speed of 232kt (430km/h), Boom says.
The pilot also extended and retracted XB-1’s landing gear for the first time, and Boom evaluated “the direction and strength of airflow across the wing, verifying its aerodynamic characteristics”.
Scholl says only two small issues arose during the second flight: XB-1’s ADS-B Out function failed to transmit the jet’s altitude, and its landing-gear anti-skid system suffered what Scholl calls a likely “spurious alarm message”.
During future flights, Boom intends to begin conducting flutter evaluations using XB-1’s “flutter excitation system”, which employs devices on XB-1’s wingtips to generate vibrations similar in effect to the dangerous condition of flutter.
Studying the aircraft’s response could help Boom identify the risk of flutter before flying the aircraft in conditions that might actually induce it, says Scholl. He adds that ground tests and simulations have suggested flutter is unlikely to occur.
XB-1 has yet to fly at supersonic speed, but Scholl hopes the jet will pass that milestone before year-end.
Boom still faces a long road to achieving its goal of developing and bringing to market an economical supersonic passenger aircraft.
Its top challenges include developing Overture’s engines. Boom had initially hoped to source engines from an existing engine producer but brought development in-house in 2022, after major engine makers stepped away from the project.
It is now working with Florida Turbine Technologies, a Kratos Defense & Security Solutions division, to produce the 35,000lb (156kN)-thrust “Symphony” engines that are to power Overture.
In addition to technical hurdles, Boom will need more investment to fund the incredibly expensive process of certificating a passenger jet and of building a production system.
