From Beijing to New York in two hours: China tests a supersonic plane (6 photos + 1 video)
It's been more than 20 years since the legendary Concorde last flew. But the Chinese company Space Transportation is reviving the dream of supersonic passenger flights. Its airliner will be even faster than NASA's "son of Concorde" X-59. 
According to the South China Morning Post, on December 17, during tests at an altitude of 20 km, the engine reached a speed of Mach 4, which is 4,899 kilometers per hour, or four times the speed of sound.
This is twice the maximum speed of Concorde (Mach 2 or 2,179 kilometers per hour), and three times that of the "son of Concorde" NASA's X-59 (1,850 kilometers per hour).
"This engine has great commercial potential for high-speed flights in near-space conditions," Space Transportation said in a statement.
The Yunxing airliner is scheduled to make its maiden flight in 2027, with its first commercial flight scheduled for 2030. Passengers will be able to observe the curvature of the Earth — the horizon will look different than at an altitude of 15,000 meters.
The engine is named Jindouyun, or JinDou400, after the cloud on which the Monkey King flew in the famous Chinese novel "Journey to the West."
"The test flight achieved key engine performance characteristics and verified critical systems including the fuel system, electrical system, and control system," the company said.
The aircraft will be built from lightweight, durable composite materials that can withstand the extreme heat generated by flying at Mach 4.
Yunxing will be capable of vertical takeoff and landing, allowing it to maneuver in tight spaces.
After a long wait, NASA finally unveiled its supersonic X-59 jet, nicknamed the “Son of Concorde,” in January.
The $247.5 million X-59, developed by Lockheed Martin, is capable of flying at 1,135 mph — faster than the speed of sound, but not Mach 4. If cleared for commercial flights, it could fly passengers from London to New York in under four hours.
