The return of supersonic passenger flights could take longer than Boom Supersonic anticipates. More than five years after United Airlines agreed to purchase Overture aircraft, the carrier’s CEO Scott Kirby believes the planned launch of commercial operations in 2029 is unrealistic. According to AeroTime, Kirby warned in an episode of the Office Hours: Business Edition podcast published on October 28 that development and certification would require more time.

In June 2021, United announced an agreement to purchase 15 Overture aircraft, with options for another 35. The schedule presented at the time called for the first aircraft to be rolled out in 2025, followed by its maiden flight in 2026 and passenger service in 2029. However, the purchase is conditional on the aircraft meeting United’s safety, operational and sustainability requirements.

Kirby did not offer a revised entry-into-service date. According to AeroTime, he said United could become the first airline to operate Overture if development succeeds, while warning that the programme still faces significant hurdles. His remarks therefore represent the assessment of an executive at a prospective operator, rather than an official announcement of a revised development schedule from Boom.

Propulsion remains one of the programme’s key development challenges. On October 22, Boom announced the completion of its first prototype turbine core, named Sprint Core, comprising the compressor, combustor and high-pressure turbine. Initial firing is scheduled before the end of November at the company’s Colorado test site, with more than 1,000 sensors intended to monitor the prototype’s behaviour during testing.

The technology is intended to support two products. Alongside Symphony, the engine being developed for Overture, Boom is working on Superpower, a 42-megawatt natural gas turbine designed to supply electricity to data centres, including those supporting artificial intelligence systems. The company presents this business as a more cost-effective way to develop the technology needed for its future aircraft engine.

Under the plans reported by AeroTime, initial Superpower deliveries are expected in mid-2027, with annual production subsequently reaching 25 units in 2028 and 50 in 2029. Boom has also unveiled a turbine manufacturing campus in Centennial, Colorado, representing a planned investment of $150 million. Operating experience and reliability data gathered from the stationary turbines are intended to support Symphony’s development, placing the energy product ahead of the aircraft engine in the current development sequence.

Overture itself is designed to carry between 60 and 80 passengers at a cruising speed of Mach 1.7, with a range of 4,250 nautical miles, or approximately 7,870 kilometres. Production is planned in Greensboro, North Carolina. Boom lists a total of 130 orders and pre-orders associated with United, American Airlines and Japan Airlines, although this should not be interpreted as an equivalent number of unconditional firm purchases.

Alongside technical development, the return of supersonic passenger services also depends on the regulatory framework. AeroTime reports that the US Federal Aviation Administration is proposing to replace the longstanding restriction on civil supersonic flights over land with rules based on permissible noise levels. The agency aims to finalise its supersonic operating and noise rules by mid-2027, but any changes would not remove the requirement to certify Overture and its engines.

More than two decades after Concorde’s final commercial flight, the prospect of restoring supersonic passenger routes continues to attract airline interest. Kirby’s comments nevertheless show that even programme partners remain cautious about the announced timeline. Overture’s progress will ultimately depend on the results of development, testing and certification, and no revised date for the start of passenger services has yet been offered.