Why does it take less time to go east than west when flying trans-pacific?

Question

I just completed a round-trip between Hong Kong and San Francisco. From SFO to HKG, it took 14 hours, while the trip from HKG to SFO took only 11 hours. I think this is consistent with other trans-pacific routes I've taken. Why?

Answer 1

The reason for this is what's called the "jet stream". The jet steam is a fast flowing, westerly air current that takes on a narrow, flattened tube shape--often spanning thousands of miles in length, a hundred miles in width, and one or several miles in height. The jet stream usually divides cold arctic air from the warmer airs to the south.



The location of the jet stream is extremely important for airlines. In the United States and Canada, for example, the time needed to fly east across the continent can be decreased by about 30 minutes if an airplane can fly with the jet stream, or increased by about the same amount if it must fly west against it. On international flights, the difference is even greater, and it is often actually faster and cheaper flying eastbound along the jet stream rather than taking the shorter great circle route between two points.

Answer 2

Jet Stream -high winds at altitudes where jest fly- makes the difference. These winds are commonly over 100 miles per hour and they usually blow from West to East. A commercial airliner maintains certain air speed. The air speed is different from ground speed. So if you have a 100 mile per hour head wind and you are flying at 500 mph airspeed, your ground speed is 400 mph. If you have a tail wind and your air speed is 500 MPH your ground speed is 600 MPH. That is what makes the difference.

Answer 3

Passing through the time zones will cause a difference in fight hours.

Answer 4

there's wind blowing at the plane so in one direction the wind is blowing against the plane making it slower and the other way it blows with the plane making it faster