Jet Stream Causes Air Travel To Go 'Almost' Supersonic ~ Shield Spirit

Thursday, January 8, 2015

Jet Stream Causes Air Travel To Go 'Almost' Supersonic

A jet stream roaring across the North Atlantic at more than 200 miles per hour early Thursday morning nearly succeeded in bringing back supersonic air travel for the New York to London route. Several flights from New York's John F. Kennedy International Airport made the trip from there to London's Heathrow Airport (from gate to gate) in about five hours and 20 minutes.

British Airways Flight 114, a Boeing 777-200 jet, took off from JFK at 10:50 p.m. ET, and landed at 9:06 a.m. local time, taking just five hours 16 minutes to make a trip that typically takes more than six hours.

At one point, according to Flight Aware, the jet was traveling at a groundspeed, which is the speed at which the plane is traveling relative to ground level, of 745 miles per hour. For comparison, the speed of sound at sea level is 761 miles per hour.

In other words, the 777 helped British Airways live up to its legacy of operating the Concorde aircraft on that route until 2003.

(The actual airspeed of the 777 was considerably lower, though, and the plane was traveling within normal design limits, below the speed of sound at altitude, according to Flight Aware data.)

The 757 has a range of about 4,800 miles, which makes some of the routes between Europe and the U.S. very close to its maximum limit, particularly when there are strong headwinds that lower the groundspeed.

Of course, the Concorde used to fly the route much faster, at speeds of up to 1,350 miles per hour. According to a British Airways fact sheet, its fastest transatlantic crossing was on Feb. 7, 1996, when the New York to London flight took just 2 hours, 52 minutes and 59 seconds.

To avoid the 200-mile-per-hour-plus core of the jet stream, where the winds are strongest, flights between the UK and the U.S. have been taking an unusual route, flying closer to Greenland, rather than heading due west across the Atlantic.

British Airways flight 117, a Boeing 747-400, arrived at JFK at 1:31 p.m. ET on Thursday, after a seven hour and 35 minute journey from Heathrow that took the aircraft across the southern tip of Greenland. Typically, flights from the UK to New York cross the Atlantic further to the south, and don't cross Greenland.

The jet stream is forecast to help spawn a series of storm systems that will barrel into northern UK as well as Ireland, bringing heavy rains and widespread winds of up to 100 miles per hour or greater through Saturday, particularly in northern Scotland, according to the UK Met Office.