Why faster to fly west to east

If the earth didn't rotate, winds would only flow north-south, migrating between the equator and the poles. But because of the earth's rotation and the Coriolis effect, these winds are pushed to the side, creating both the swirling shapes of hurricanes and the undulating pattern of the jet stream. And this is why that flight from LA to New York is shorter than vice versa; it benefits from a jet stream-assisted tailwind at its back. So earth's rotation certainly has a some effect on air travel times, but in a much more indirect way.

For you. World globe An icon of the world globe, indicating different international options. Get the Insider App. Instead of flat latitudinal lines, most jet streams form in rather meandering eastward waves across the planet.

That means the fastest path between two destinations is not necessarily as the crow flies. Today, airlines employ data from satellites and other weather-tracking tools to map the most efficient jet stream routes. It occurs most often when a plane treads the line between cold air on one side and warm air on the other.

First is airspeed — how fast the wind would feel if you stuck your hand out the window. The second is ground speed — how fast the plane is moving over the ground.

When you fly in the jet stream, your airspeed always stays the same, but your ground speed can change a lot because the air around the plane is moving. On the way to Hawaii, I was flying with an airspeed of mph. But because the jet stream was blowing against my airplane — called a headwind — at mph, I was actually only moving across the ground at mph. But flying from Hawaii to New Jersey, the jet stream blows from behind the plane and pushes it forward. I was still flying with an airspeed of mph, but the mph tailwind meant that my airplane was moving across the ground at mph.

When pilots plan the route of their flights, they often use weather forecasts to find where the jet stream is blowing. Think of it kind of like walking against the wind. The jet stream is the real reason your flight time varies depending on the direction of your destination. Jet streams are air currents that happen at very high altitudes, including those which planes frequently fly in.

So, yes, the rotation of the earth is a factor in this scientific dilemma, but it is not the main reason why your flight time is different depending on the direction of your flight. If your plane is flying along a jet stream going east, it can really pick up some speed.