Boeing co-backed supersonic jet maker Aerion said on March 3rd Berkshire Hathaway’s private aircraft firm, NetJets, has obtained purchase rights for 20 of its AS2 business jets.

The AS2 will be powered by engineered synthetic fuel and can reach supersonic speeds of up to Mach 1.4, or about 1,000 miles (1,610 km) per hour, which is 50% faster than conventional business jets, Aerion said.

Production of the jets will begin in 2023 at the firm’s Aerion Park facility in Melbourne, Florida, with the first 300 AS2 aircraft planned for the first decade of production, the company said.

Aerion’s global order backlog for the AS2 is now valued at more than $10 billion.

The company said it will also develop a supersonic flight training academy for civil, commercial and military supersonic aircraft in collaboration with Berkshire’s professional aviation training provider, FlightSafety International.

U.S. startups Aerion, Boom Supersonic and Spike Aerospace are working to reintroduce supersonic passenger travel for the first time since the Anglo-French Concorde retired in 2003.

General Electric Co’s GE Aviation unit has said it completed initial designs for the new Affinity turbofan engine, which will be used in Aerion’s AS2 jet.