British Airways set a new New York–London subsonic commercial aircraft speed record on 9 February with the BA112 landing in London 4 hours 56 minutes after departing New York. Accomplished with a Boeing 747-400, the flight took advantage of a well-placed and strong jet stream to reach London in under 5 hours.

The BA112 flight path

The previous record was held by a Norwegian 787, which made the flight from New York to London’s Gatwick Airport in 5 hours 13 minutes.

Taking advantage of the jet stream

Flights traveling eastbound over the North Atlantic this week are taking advantage of the strong, well-placed jet stream to decrease flight times and fuel consumption. The image below shows flights over the North Atlantic at 9 February 0600 UTC.

Coming back the other way, flights are routing to the north of the jet stream over Greenland. This is having a varying affect on flights depending on origin and destination. Some flights are adding more than 60 minutes, while others that manage to avoid the jet stream entirely are in some cases arriving early.

Ground speed vs airspeed

The speed displayed for every flight on Flightradar24 is ground speed—that is, how fast the aircraft is traveling over the ground. This data is received from the aircraft via ADS-B. Some flights also broadcast various air speeds, including indicated airspeed, true airspeed, and Mach value. During its speed record cruise across the Atlantic, BA112 traveled at a consistent Mach 0.86 or 86 percent of the speed of sound. Because the speed of sound is relative to the air mass in which the aircraft is traveling, the flight does not ‘break the sound barrier’.