Updated on February 5, 2019, to include additional images.

Three upstart companies – Boom Supersonic, Aerion and Spike Aerospace – seem to be edging closer towards the reintroduction of supersonic flight for civilians. Firm believers in the commercial success of transoceanic routes, all three companies have received orders for their aircraft and hope to start delivering them in the mid-2020s.

Boom recently concluded its second investment round collecting a total of $100 million to help assemble the first prototype of its Overture plane (cruising speed of Mach 2.2). Having already test flown its subscale prototype, Spike is reportedly in the process of selecting an engine for its S-512 (Mach 1.6) aircraft. Meanwhile, Aerion is already considering commercial variants of its AS2 (Mach 1.4) supersonic business jet. While Boom is focused on supersonic civilian airliners, Aerion and Spike are exclusively focused on the private business jet market.

Most of these companies advertise their planes as not only “the fastest” aircraft, but also promising “low-boom” flight. In fact, the future of these projects hinges mostly on whether the new supersonic aircraft will be able to meet current noise standards.

Although regulations are being loosened up in the U.S., civilian supersonic flight overland is restricted globally due to the “sonic boom” that such aircraft produce. Aside of aerodynamic innovations and new materials, developers are putting their bets on new engine designs, which they believe hold the potential to building a “quiet” supersonic plane.

The Overture

Boom Technology expects the first flight of its supersonic aircraft by the end of 2019. On January 4, 2019, the company announced it managed to collect $100 million of funds in its second research for investors. Founders and early backers of companies like Google, Airbnb, Stripe, and Dropbox are investing in Boom along with Investors, led by Emerson Collective, include Y Combinator Continuity, Caffeinated Capital, and SV Angel. In total, Boom managed to receive $141 million of funding.

The company’s main objective now is to complete the next phase of its project: get its supersonic demonstrator plane, the XB-1, in the air. The XB-1 (also known as Baby Boom) is a ⅓-scale manned Overture prototype which is currently under construction in Centennial, Colorado. It is powered by General Electric J85 engine. Boom will be announcing the final engine for the Overture aircraft later this year.

The XB-1 subscale prototype (Image: Boom Supersonic)

The final Overture aircraft should be half the size of the Concorde. It will only carry 55 passengers (against 100 for its famous ancestor). “Overture fares will be similar to today’s business class,” said Blake Scholl, founder and CEO of Boom Supersonic, adding that, “ultimately, our goal is to make high-speed flight affordable to all.”

The Overture (Image: Boom Supersonic)

Three engines will allow the Overture to fly further, but use less fuel and be less noisy, with a sonic boom "at least 30 times quieter" than the Concorde, claims the company. The first scheduled flight of the Mach-2.2 (2715 km/h) commercial airliner is expected to take place in mid-2020s. The startup says its supersonic aircraft will be flying oceanic routes. Pre-orders were placed by Virgin Group and Japan Airlines for a total of 30 Overture aircraft.

The Overture interior (Image: Boom Supersonic)

The Aerion AS2

Aerion Supersonic announced in October 2018 it had concluded the conceptual design phase for its 12-seat supersonic business jet, the AS2. The company says it is now aiming to conclude the preliminary design stage in June 2020.