Anonymous
Anonymous asked in Science & MathematicsAstronomy & Space · 1 decade ago

# Are aircraft flight times affected by the rotation of the earth?

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I went through some resources that says earth rotation does not affect flight times. Yes, the rationale given seems to be true but with application of different scientific calculations, I can see it has something to do though not in significant amount or through some indirect effects.

It is said that the flight times are affected by the winds. The earth's rotation results to circulation of the wind which is either east or west bound. The head and the tail winds have impact on flight time differences. These winds of course are largely related to earth rotation, thus how could it be that flight times are not affected by earth rotation while the winds got effect on it, and in fact such wind is being affected by earth rotation. It simply shows the earth rotation affects the wind, and the wind affects the time flight thus gives a hint that earth rotation has indirect impact to the aircraft speed thus affecting the flight times. The counterforce of the wind affects the speed of an aircraft though in a very less extent but such less difference in speed counts a lot in calculating long distances.

In conclusion, I believe it does affect.

" One of the factors that influence flight times is the earth's rotation and its drag effect on the atmosphere and the different layers. The true picture becomes even more complex, because you have to factor in:

1. geodesic paths (shortest route - remember, the Earth is a sphere and not flat - cartography distorts the pole regions, hence flight paths over the north pole come close to a geodesic for SIN - EWR)

3. Earth's rotation and its effect on general wind directions on the northern and southern hemisphere.

4. Allowed flight corridors/

The mathematically inclined could solve this complex set of equations using linear programming (which, by the way, is done by the flight computer before the pilot makes the announcement of the estimated flight time after boarding)."

(I could have elaborated some physics calculations and equation in here to explain but I feel I do not need to push myself further to depend my own understanding on this logic situation. This is not a physics class anyway.)☺

• Anonymous

Only to the extent that the rotation of the Earth affects the wind systems of the world. Aircraft are only affected by the movement of air, and air rotates in general with the Earth. However, the Coriolis effect causes rotatary wind systems as a result of the Earth's rotation and this does impact on aircraft. Hence planes fly a different route and at a different height gooing EW and WE across the Atlantic.

• Anonymous

No.

Speed can be a confusing topic when considered from an aerospace engineering standpoint. For this question, we need to consider two "concepts" of speed. The first is the speed of an object through space, which we will consider as the speed of the Earth's rotation about its axis. If we consider this concept, then you, sitting at your computer, are probably traveling somewhere around 735 mph (1,183 km/h) through space, depending on your location relative to the equator (are you wearing your safety helmet?).

The second concept of speed is an object's speed relative to the Earth's surface. In this case, you, sitting at your computer, are traveling at 0 mph relative to the Earth. Now let us consider what would happen if you suddenly stood up and started running (run Forrest, run). No matter which direction you run, your speed relative to the Earth would be 10 mph (16 km/h) or so (80 mph if you are a Cheetah). If you were running to the west, against the Earth's rotation, then your speed through space would be 725 mph (1,166 km/h). Of course, if you ran the opposite way, it would be 745 mph (1,199 km/h). Your speed relative to the Earth is the same no matter which way you run. It isn't affected by the rotation of the Earth.

Now stop running. If you were to jump straight up in the air, would the Earth rotate beneath you? (Those who do believe that the Earth rotates around them may want to stop reading right now.) No, because when you left the Earth's surface, you were traveling at the same speed as the surface, so, in essence, the Earth matched your speed through space while you were in the air! The same condition holds true for an airplane as it travels from Los Angeles to Bombay. If we were to ignore the winds, no matter which direction you flew from Los Angeles, the speed of the aircraft relative to the Earth would be the same. While the aircraft's speed through space would change, the effect of the Earth's rotation remains constant, and in effect is "cancelled out" no matter which direction you travel. In other words, the speed of the rotation of the Earth is already imparted to the aircraft, and the Earth matches that speed during the entire flight. (Of course, in the case of spacecraft, these speeds become very important.)

So, the end result of that long discussion is that the rotation of the Earth has no effect on the travel time of an aircraft. Actually, as you suggested, it is the headwinds and tailwinds that cause the change in travel times. Sometimes it is hard to believe that the winds can have that much effect, so let us consider the problem a bit more in depth. In the example given, the flight from Bombay to California (east) is 23% shorter than the trip from California to Bombay (west). This means that the speed of the trip east must be 23% faster. The prevailing winds pretty much anywhere that we are talking about blow from west to east, so when we are traveling east, we get a speed gain, and when we travel west, we get a speed penalty. Now, if we are to assume that the winds are identical on both days we fly, then the wind speed only needs to be equal to 11.5% of the aircraft's speed! This would cause a difference between the speed to the west and speed to the east of 23%! The cruise speed of the extended range Boeing 777 is about 550 mph (885 km/h) at 35,000 ft (10,675 m). This means that the winds only need a speed of about 65 mph (105 km/h) (good kite weather). Believe it or not, 65 mph is a very typical wind speed at such a high altitude. Speeds of over 100 mph (160 km/h) are not uncommon. If we wanted to make things more complicated, we could consider a region of high speed flow called the jet stream that flows eastward, and if an aircraft can take advantage of these winds, then the travel time can be reduced further. (We could get even more complicated and talk about El Nino and La Nina, but I think we have blamed them for enough already!)

So what is the bottom line? The rotation of the Earth does not effect the travel time of an aircraft, and, more importantly, a mere 65 mph wind is more than enough to cause a difference in travel time of five hours when you are traveling long distances!

• ?
Lv 4
4 years ago

From my extremely constrained understanding of Geography aircrafts fly alongside the longitudinal lines of the earth presently as quickly as they attain cruising altitude, (longitudes are those imaginary lines which chop up the earth into 360 equivalent products vertically ) . There are exceptions to this even with the undeniable fact that, from time to time aspects mutually with undesirable climate and no-fly zones reason pilots to devise a somewhat much less direct direction however the trouble-free theory is to shuttle alongside the shortest distance between 2 factors that's a at as quickly as line. by using around shape of the earth longitudes are curved yet it somewhat is the shortest distance u can get between any 2 factors on a sphere. And it would not somewhat count style how briskly the airplane strikes as long because it could proceed to be airborne by using fact the linked fee of rotation of the earth is extremely sluggish.desire this helps!

Sure, if you leave from the west cost and fly east you lose an hour in each time zone. If you do the reverse, you gain an hour in each time zone. However, since most planes don't fly at the speed of light, then a 5 hour flight takes 5 hours no matter which direction you fly in. Then again at 500 mph you will cover 500 miles in 1/5th the time it takes to fly 500 miles at 100mph.

Yes, but mostly by winds caused by that rotation, which prevail E->W. That's why you fly from N.America to Europe just a little longer than back.