Transatlantic flight may never return to the halcyon days of Concorde, but recent weather events have conspired to bring a reminder of what super-quick transatlantic travel was like.

It was reported last week that a Boeing 777 en route from JFK in New York, to London Heathrow attained an air speed of 1199kph, well above its cruising speed of 950kph. This is only just below the speed of sound, 1225kph, and not too far away from the records set by the world’s most famous, but no longer operational, supersonic passenger jet, Concorde.

Back in its heyday, the famous delta-wing aircraft with the droop nose-cone had a maximum speed of 2179kph. On 7th February 1996, aided by a tailwind of 280kph, a BA operated aircraft was timed between take-off and touchdown at two hours, 52 minutes and 59 seconds. It is likely that some passengers spent more time in the departure lounge than they did on the actual flight.

Last week’s flight, timed at five hours and 16 minutes is obviously well short of that record, but it was around 90 minutes inside its scheduled time thanks to winds approaching 300kph.

These super-quick transatlantic flights are the result of the jet stream, a narrow band of wind which blows at between 25,000 and 35,000ft. (Aircraft cruising altitudes are always in feet, not the more widely used metres.)

This can provide a corridor of tailwinds for those aircraft heading from North America to Europe. The corridor can be quite narrow, less than 20km wide and 700m deep. A great deal of planning is required to make full use of it, because the surrounding region is one of great turbulence.

The jet stream is the result of a sharp temperature contrast. There is always a decrease in air temperature between the tropics and the polar regions, but particularly cold weather across North American in recent days has been swept across the Atlantic and produced a much greater contrast than usual.

Although jet streams may be of benefit to transatlantic flights, they are not without their own hazards and problems. The area on the northern side of the jet stream, in the cold air, is ripe for the development of underlying frontal depressions. The worst winter storms which hit the UK and northwestern Europe are often associated with an exceptionally strong jet stream.

How ironic it would have been if that record-breaking flight had been forced to delay its landing because of stormy weather at Heathrow.

Source: Al Jazeera