Flying phenomenon

[Sean Clayden]

Does flying against or with the earths rotation make a difference ?

Example, flying from London to New York or from New York to London ?

[Neverfly]

Does flying against or with the earths rotation make a difference ?

Example, flying from London to New York or from New York to London ?

It's more dependent on Weather than Earths Rotation.

Now... If Earth had Zero Atmosphere...

[grant hutchison]

The jetstream blows west to east, and has a rather variable path around the globe. IIRC, it can occasionally shorten the duration of west-east flights at high altitude.

Grant Hutchison

[G O R T]

If you fly west over the equator at 1670 kph (groundspeed), time stands still!
If the sun is almost down, you're in the twilight zone!
This does not work flying east.

[Sean Clayden]

Its just that i'm a taxi driver and when I have collections from the airport, form america flights are on time or late, from asia they are always early ?

[grant hutchison]

Its just that i'm a taxi driver and when I have collections from the airport, form america flights are on time or late, from asia they are always early ?

Depends on whether delayed departures are equally common in both groups.
Does something happen on the ground in the USA (for instance, security checks) which leads to more delayed departures?

Grant Hutchison

[JustAFriend]

Does flying against or with the earths rotation make a difference ?

A difference to WHAT?

[Sean Clayden]

Do you fly faster with the earths rotation or slower against it ?????

[NEOWatcher]

Depends on whether delayed departures are equally common in both groups.
Does something happen on the ground in the USA (for instance, security checks) which leads to more delayed departures?

That could be one factor.
Another could be the number of connecting flights. Any international flight could be dependent upon dozens of other connecting flights.
There might also be a bit more or less "fudge factor" built into the schedules somewhere.
U.S. Might be a bit more tolarant of latecomers.
U.S. Might have more of an issue of congestion on the ground before takeoff.

Just a few things off the top of my head.

Do you fly faster with the earths rotation or slower against it ?????

NO.

You are taking off with the Earth's momentum already part of your own.

[pzkpfw]

Wouldn't there be an effect similar to rocket launches?

(i.e. why they are launched from where they are, in the direction they are?)

[ToSeek]

The jetstream blows west to east, and has a rather variable path around the globe. IIRC, it can occasionally shorten the duration of west-east flights at high altitude.

Grant Hutchison

I fly from Baltimore to Los Angeles annually, and the scheduled duration for the eastbound flight is always less than that for the westbound. So it's pretty consistent.

[grant hutchison]

I fly from Baltimore to Los Angeles annually, and the scheduled duration for the eastbound flight is always less than that for the westbound. So it's pretty consistent.

That's interesting. The jet stream tends to wander, but it is fast. Perhaps the airlines on that route can reliably pick it up somewhere along the way, for long enough to justify some detours if necessary.

Grant Hutchison

[Ara Pacis]

Wouldn't there be an effect similar to rocket launches?

(i.e. why they are launched from where they are, in the direction they are?)

Not unless the plane is flying out of the atmosphere. Coming or going, the planes are taking off and landing at locations that are also moving, as well as travelling through a medium that is also moving. It's the same frame of reference.

[Bozola]

Does flying against or with the earths rotation make a difference ?

Example, flying from London to New York or from New York to London ?

Yup. The Hafele-Keating experiment showed that you'll lose nanoseconds flying east, but gain them flying west, compared to a stationary clock at your point of origin.

[Torsten]

That's interesting. The jet stream tends to wander, but it is fast. Perhaps the airlines on that route can reliably pick it up somewhere along the way, for long enough to justify some detours if necessary.

Grant Hutchison

I've noticed the same thing on Vancouver-Toronto flights. Pilots have often mentioned in their in-flight commentary on the eastbound trip that we were getting the benefit of the jetstream or other high winds aloft.

[Torsten]

Yup. The Hafele-Keating experiment showed that you'll lose nanoseconds flying east, but gain them flying west, compared to a stationary clock at your point of origin.

Shhhh. You know what happens when Hafele-Keating is mentioned. . .

[Bozola]

Shhhh. You know what happens when Hafele-Keating is mentioned. . .

Last time it took a fortnight to get all the planaria out of the tesseract.

[trinitree88]

I've noticed the same thing on Vancouver-Toronto flights. Pilots have often mentioned in their in-flight commentary on the eastbound trip that we were getting the benefit of the jetstream or other high winds aloft.

see:http://squall.sfsu.edu/crws/map_info...ream_info.html

Torsten. Correct. Generally the airlines follow the computer maps, and use jet-stream assist to save fuel Eastbound, while avoiding jet-streams when Westbound for the same reason. The computers map out the path of least fuel. Must make it a little tricky for flight plans, as most flights stick pretty close to Victor Airways...highways in the sky. As for ground effects, the viscosity of air and laminar shear effects means the air at ground level flows pretty close to the planets' latitudinal rotational velocity....kind of like the edges of a stream sticking to the banks while the center flows faster..(which is why you canoe near the edge going upstream, but in the middle going down in a deep river). So for the taxi guy, the airlines are supposed to take it all into account and get them there on time....and I think it matters the most whose airline has the best ontime rate, which these days seems slipping. pete

[Torsten]

trinitree: Nice resource there.

I used to own a plane, but it was a long time ago (sold it when my first child was born - she's in university now). To the degree that terrain and weather allowed me to take advantage of winds aloft forecasts on a long cross country flight, I would try to do that. But most of my flying was on the west coast, and the main issue was keeping between the mountains and out of the scud.

I've often wondered how flexible flight planning is for the airlines because they typically cruise above the Victor airways, but I haven't bothered to ask, i.e., how much direct routing can ATC typically accomodate above the airway system? I imagine over the US this is more of a challenge than over northern Canada (southern Canadian airspace is probably much like USA). Maybe Larry Jacks could comment here?

[pzkpfw]

Not unless the plane is flying out of the atmosphere. Coming or going, the planes are taking off and landing at locations that are also moving, as well as travelling through a medium that is also moving. It's the same frame of reference.

I'm sure atmospheric effects (jetstream etc.) outweigh all other effects, but I'm not so ready to dismiss Earth rotation effects (which is what the OP was about).

What comes to mind is the difference in draft of two ships passing at the Equator - one with the Earths rotation and one against. Or is that a myth?

Would there be no effect at all on aircraft?

(Perhaps assume the air is perfectly still (relative to the ground) all around Earth (i.e. rotating with the Earth).)

[Torsten]

I'm sure atmospheric effects (jetstream etc.) outweigh all other effects, but I'm not so ready to dismiss Earth rotation effects (which is what the OP was about).

What comes to mind is the difference in draft of two ships passing at the Equator - one with the Earths rotation and one against. Or is that a myth?

Would there be no effect at all on aircraft?

(Perhaps assume the air is perfectly still (relative to the ground) all around Earth (i.e. rotating with the Earth).)

Well, NEOWatcher mentioned earlier that each aircraft already has momentum due the Earth's rotation, regardless of the direction it's flying. But what about flying to a different latitude, i.e., northerly or southerly flights. In the northern hemisphere, if there were no wind, and you departed on a due north bearing, and made no adjustments to your bearing as you flew, then the easterly momentum you have at take-off ought to cause your path over the globe to drift to the east. Flying south, you should drift to the west. Don't long distance ballistic flights have to take this into account?

Can't comment on the ships' draft issue.

[hhEb09'1]

What comes to mind is the difference in draft of two ships passing at the Equator - one with the Earths rotation and one against. Or is that a myth?

Sort of. The two meter tall Vening Meinesz carried his gravimeters on submarines all over the world, and adjusted his measurements for that Eötvös correction. It's small, but significant in gravity studies. That link says it's on the order of 7 parts in 10,000.

[Ara Pacis]

I'm sure atmospheric effects (jetstream etc.) outweigh all other effects, but I'm not so ready to dismiss Earth rotation effects (which is what the OP was about).

What comes to mind is the difference in draft of two ships passing at the Equator - one with the Earths rotation and one against. Or is that a myth?

Would there be no effect at all on aircraft?

(Perhaps assume the air is perfectly still (relative to the ground) all around Earth (i.e. rotating with the Earth).)

I would expect the difference in draft to be based on tonnage, bouyancy and hull design, not earth's rotation.