New 990mph supersonic jet passes major milestone

A "son of Concorde" jet which could fly from London to New York in under four hours has passed a milestone test. NASA’s X-59 supersonic research aircraft flew with its "wheels-up" for the first time this month.

Flying with the landing gear up paves the way for researchers to examine the aircraft's streamlined profile, a key design element which would ensure the X‑59 can fly faster than the speed of sound, making just a quiet thump instead of a loud sonic boom.

The aircraft is projected to fly at Mach 1.5, or about 990 mph (1,590 kph), meaning it could potentially fly non‑stop from London to New York in approximately three hours 44 minutes.

Concorde could reach a maximum cruising speed of Mach 2.04, or 1,354 mph (2,179 kph), which is more than twice the speed of sound. This supersonic speed allowed it to reach the Big Apple in about three hours.

Usually, commercial flights generally take around seven to eight hours.

The X-59's relatively quiet flying should help solve the noise problem which has made such planes unsuitable for flying over populated areas.

NASA said experimental aircraft typically make their earliest test flights with the landing gear down, then begin retracting it after successfully meeting performance benchmarks.

The X‑59 flew wheels‑up for the first time on April 3.

Piloted by NASA test pilot Jim "Clue" Less, the aircraft departed from its home base at NASA’s Armstrong Flight Research Center in Edwards, California, and flew for 90 minutes, soaring up to 20,000 feet.

NASA said on Wednesday: "The X-59 has made eight flights as of April 10 as it continues its test flight envelope expansion campaign.

"The X‑59 is at the centre of NASA’s Quesst mission to enable quiet commercial supersonic flight over land."