Tuesday, January 13, 2015

Surging jet-stream winds hinder US-bound flights from Europe


NEW YORK — Winter weather is putting a kink in air travel plans as the North Atlantic jet stream hits peak intensity.


Stronger westerly headwinds for U.S.-bound flights are stretching out travel times, forcing some planes to stop for refueling. Trips such as London to New York, a busy business route, are running almost eight hours — 45 minutes longer than voyages in September.


Two Philadelphia-bound American Airlines flights, one from Brussels and the other from Amsterdam, had to touch down on Jan. 11 to refuel in Bangor, Maine, said Scott Ramsay, the carrier's managing director of its integrated operations center. The journey from Brussels took 9 hours and 16 minutes, about an hour more than three months earlier, according to industry data tracker FlightAware.


"You know you're going to be in trouble on the way back," Ramsay said. "You try to pick out ways that you can get around the headwind."


If you're headed in the opposite direction, you might catch one of the shortest flights on that route yet. A British Airways flight from New York to London earlier this week approached the speed of sound, buoyed by the jet stream, and the Boeing 777-200 made the journey in just over 5 hours, according to FlightAware.


The headwinds caused by the winter jet stream, which is at its most intense during this season when the differences in temperature between the equator and the North Pole are the greatest, have been ratcheting up in recent years.


Flights across the Atlantic to eastern U.S. cities in December 2013 averaged 19 minutes later than a year earlier, according to industry data tracker MasFlight.com. Travel times in December 2014 were similar to those in 2013, MasFlight's data from more than 1,300 flights a year showed.


With the threat of increasingly strong headwinds every winter, airlines face higher costs on those westbound flights with the use of extra fuel and the crew's time.


"When you were planning to fly non-stop, stopping for fuel costs money," said George Hamlin, president of Hamlin Transportation Consulting, who has more than 40 years of experience in commercial aviation and aerospace.


The jet stream is a river of winds that circles the earth from 30,000 to 40,000 feet (9,000 to 12,000 meters) above the surface and can reach speeds of 200 miles per hour or more, according to the National Oceanic and Atmospheric Administration.


Westbound flights over the Atlantic have to either fly north or south of the jet stream or else cruise at a lower altitude to avoid headwinds of about 200 miles (321 kilometers) per hour. Both options burn more fuel, forcing carriers to pre-plan fuel stops for some U.S.-bound flights.


"It's going to become a more difficult proposition over time for airlines to plan for the days in which there's simply no altitude and no routing that is going to get them from point A to point B, east to west, with the normal fuel loads that they would carry," according to John Nance, a former commercial and military pilot who is now a Seattle-based consultant.


The delays also put pressure on passengers racing to make connecting flights, causing some airlines like American Airlines to adjust block times in the winter for passenger connections, according to spokeswoman Andrea Huguely.


Since November, a strong low-pressure system over the polar regions and high pressure in the tropical Atlantic has created "a funneling effect" which is intensifying the jet stream, said Alex Sosnowski, a meteorologist at AccuWeather, Inc. in State College, Pennsylvania.


It isn't unusual to see these patterns set up over the course of the year, he said. There are indications that the forces that are enhancing the winds now may relax later this month.


— With assistance from Brian K. Sullivan in Boston.



No comments:

Post a Comment