why do flights fro dc to.hanoi go eastward than westward

Why do flights from DC to Hanoi go eastward rather than westward?

Overflight Permits and Airspace Management: The degree of airspace management and transit permissions required by each country can also affect route selection. As a factor, some flights will fly over certain countries or regions, which may ultimately affect their flight paths. For example, a flight to Asia may fly over the airspace of Canada or Russia, or even other countries, resulting in an eastward arching route. At Norfolk State University City Airport in the northern United States, this eastward route does not have any direct benefits. This alternative route is closer to the actual route to the airport, while a more westward route would require a very significant change of direction。

Regarding distance and fuel consumption: Even though it seems counterintuitive at first glance, flying east will improve fuel efficiency and obtain a more direct route. In this case, the Coriolis effect caused by the rotation of the earth causes the northern atmosphere to deflect to the right, allowing aircraft flying eastward to take advantage of this path change to shorten the actual flight distance and flight time. In other words, a flight from Washington, DC to Hanoi will fly east due to a combination of factors such as large circles, favorable jet stream alignment, airspace management considerations, airport location, and fuel efficiency and flight time optimization.

Flights from Washington, D.C., to Hanoi move east for the simple reason of the rotation of the Earth and orbit around the sun.

The equatorial surface of the Earth completes a full revolution every 365.25 days, and because the surrounding lands do not share the same elevation, the result is a slight wobble when the surface is viewed vertically. Thus, during winter months-midwinter months-180-degree sunshine occurs only when the sun is over the north pole. This makes the polar separation between the two cities very sizeable, with the approximate equator at 47°N and poles at -69°S. In turn, with great latitude difference, the sun rises in the east, sets in the west, and stays above the horizon most of the day during summer.

Flights taking off from Washington, D.C., to Hanoi thus move eastward because of the rotation of Earth and its orbit around the Sun. They leave the equator along the axial tilt of the Earth, the Northern Hemisphere follows, and then the Southern Hemisphere. With increasing distance from the equator, the angle between the sun and the airplane increases, which causes the sun to be lower in the sky and to move westward according to the observer's direction.

It should be kept in mind that the difference between Washington, D.C., and Hanoi depends on the respective time zone and whether the flight is affected by the daylight saving or not. However, it helps to understand that irrespective of the time of the year, the same rationale can be put forward for which flights from Washington, D.C., to Hanoi tend to move towards the eastern direction.

The flight from Washington, D.C. to Hanoi flies east across the Atlantic Ocean, Europe, and then to Asia, rather than west. This is the origin of the Great Circle Route, which is the shortest distance between two points on a sphere (earth). In fact, from a globe, the Great Circle Route from Washington, D.C. to Hanoi flies over the Atlantic Ocean and Europe, then into Asia and finally to Vietnam. This route is shorter, more efficient, and more cost-effective because it bypasses the wider Pacific or South China Sea area and flies more directly to Vietnam via Southeast Asia, which is also more time-efficient. This is a strong wind at high altitude, so it has a great impact on the flight planning process.

Generally speaking, in the Northern Hemisphere, the jet stream flows out from high in the troposphere and blows from west to east. Tailwinds are more favorable to eastward routes than westward routes because they blow in the same direction. Therefore, flying eastward can save fuel and use tailwinds to increase speed, while flying westward against the jet stream at the same altitude and speed is both time-consuming and fuel-intensive. The Coriolis effect has little effect on routes and flight plans - instead it becomes turbulence, overflights, wind direction, weather, etc., all of which easily give way to the route itself, allowing the flight to fly east without question. So the advantages of flying east seem to be more. Geopolitically and operationally, it may be more difficult to get permission to fly if you fly west, without alternate or emergency airports... Flying east is the standard route. The eastern route from Washington to Hanoi. In short, the normal route for pilots from Washington to Hanoi is east because the normal route is the most direct, the flight time is short, the airfare discounts are not in line with the cost of the trip, and there are usually good preferred seats. That's it.