The Return to Flying Faster Than Sound Will Start Small

The Federal Aviation Administration is resurrecting the dream of passengers flying faster than the speed of sound after it recently proposed lifting a ban on supersonic flights over land, which has been in place for more than five decades.

The catalyst for the proposed rule change, which is now open for public comment, comes from data collected on flights of NASA’s X-59 aircraft, an experimental supersonic plane built by Lockheed Martin Corp. This long, sleek jet began flying in October to test a design that mitigates the continuous boom that takes place when an aircraft breaks the Mach 1 sound barrier, which is about 678 miles an hour at an altitude of 30,000 feet. The X-59 flies as fast as Mach 1.4 and reduces the boom to a muted thud that shouldn’t disturb people on the ground too much.

Commercial passengers haven’t been able to break the sound barrier since the Concorde, which operated from 1976 to 2003. The plane’s four engines guzzled fuel at low speeds, and the aircraft rattled windows and set off car alarms when landing or taking off. The plane was limited to a handful of airports because of the noise and was retired because of economics and safety, especially after a July 2000 accident that killed all 109 passengers and crew as well as four people on the ground soon after takeoff near Paris.

It seems almost absurd that commercial flyers had an option to travel much faster in the 1970s than today. The decades it has taken just to get to the discussion about lifting the overland ban speaks to the complexity of the physics and the huge risks any aircraft maker would undertake to build a civilian plane that flies beyond the speed of sound. There will be no mad dash to build such an aircraft, and it’s highly unlikely to start with an airliner. If the overland bans are lifted in the US and Europe — whose regulator, the International Civil Aviation Organization, will need to get on board — the return of civilian supersonic travel likely will come as a private jet.

The market is large enough among high-net-worth individuals, private-jet fleet operators and heads of state — customers willing to pay a high price for speed or bragging rights — to provide the required volume for such a plane to be profitable, Rolland Vincent, an aviation consultant, said in an interview. Engineers will have to figure out how to create that sleek design that mitigates the boom while providing space in the cabin for at least eight passengers who have room to stand up, said Vincent, who has done work for clients to study supersonic opportunities.