It is significantly faster to fly from North America to Europe (eastbound) than it is to fly the reverse route. This is due to the jet stream, a powerful high-altitude wind current that flows from west to east across the Atlantic. When flying toward Europe, aircraft can "hitch a ride" on these tailwinds, which can sometimes reach speeds of over 200 mph, potentially shaving over an hour off the flight time. For example, a flight from New York to London might take 6.5 hours, while the return trip against those same "headwinds" can take nearly 8 hours. Pilots frequently adjust their flight paths to either maximize this boost when heading east or avoid the strongest resistance when heading west to save fuel and time.