Flying into stiff winds slows a plane’s progress - possibly eating into the minimum fuel reserve of 45 minutes of travel time beyond a designated diversion airport. That could force a fuel stop.
In December, winds blew at about 54 miles per hour, compared with the 28 miles per hour historical average.
A few of the December fuel stops were planned before jets left Europe, McCarthy said.
The airports typically used for refueling are in Eastern Canadian cities such as Gander, Newfoundland, and Goose Bay, Labrador, as well as Boston, she said.
The North Atlantic’s prevailing winds come from the west, which means that flights to the United States from Europe usually take longer than eastbound trips.
Newer, more efficient planes have reduced the need for scheduled fill-ups, which were more common in the early days of jet aviation.
But today, the type of plane used is a factor.
All of the December stops were by Boeing 757-200 jets flown by United Continental’s Continental unit on routes such as Stuttgart, Germany, to Newark, which is about 4,540 miles. The planes departed with full fuel tanks, McCarthy said.
The plane carries 175 passengers and has a maximum range of about 4,450 miles, according to Boeing’s website.
McCarthy said winglets and lighter carbon brakes were installed years ago to minimize fuel burn.
The winds have also affected new service from Washington to Paris and Amsterdam, she said.
United Airlines, whose parent merged with Continental in 2010, flies the routes in question with bigger, longer-range Boeing 767 and 777 jets - making fuel stops for those planes unnecessary.
The US Transportation Department’s Office of Inspector General in 2008 responded to a query from Senator Frank Lautenberg, a New Jersey Democrat, about reports of more planes landing at Newark because of low fuel.
The department said such fuel declarations had increased for flights into Newark, though “there were no instances of aircraft landing with fuel levels below those required’’ by the Federal Aviation Administration.
Two-thirds of the declarations were on international flights, and the FAA would review the matter, the department said.
The FAA said yesterday that it “is aware that United Airlines aircraft have made more unscheduled fuel stops this year than last year and we are looking into the issue.’’
The Wall Street Journal reported on the unscheduled stops yesterday.
