Speedy jet stream propels planes across Atlantic

Near supersonic? Speedy jet stream helping planes reach London quicker

Digital News Editor
Saturday, January 10, 2015, 11:26 AM -
Many planes, despite leaving late from New York’s JFK Airport, arrived at Heathrow earlier than expected on Thursday – with some flight times coming in almost an hour quicker than originally scheduled.
RELATED: Jet stream – How does it affect UK weather?
According to the BA website, flight BA1515 departed 40 minutes late from New York but still arrived in London 16 minutes earlier than scheduled – 56 minutes quicker than expected. Flight BA0172's journey was also around an hour shorter than earmarked.

Source. BA
Mashable reported on Thursday that the jet stream was making planes fly at “near-supersonic” speeds. Several planes reached London from New York in around five hours and 20 minutes, whereas normal flight times between the two cities takes more than 6 hours.
It said, according to Flight Aware data, the British Airways Flight 114 at one point travelled at a groundspeed – the speed at which the plane is travelling relative to ground level – of 745 miles per hour.
In comparison, the speed of sound at sea level is 761 miles per hour. Mashable did point out though that the actual airspeed of the plane was considerably lower, with the plane travelling within normal design limits at altitude.
The jet stream is a fast-flowing ribbon of air that circles our planet at 30,000 feet, around the altitude that planes fly, reaching speeds of over 200 mph. This jet of air moves weather systems around the globe and can help or impede air travel.
Planes going the other way, from London to New York, can take longer because either the jet stream is too strong or it forces planes to take detours.