V-Flyer

Been studying the various trans-Atlantic crossings on my Iphone Virgin App. It appears that the routes across the pond vary considerably, in particular the flights to Florida. Some seem to route toward the northern north Atlantic then down the Eastern seaboard, whilst others seem to take a more direct route.

Other than weather/traffic/ATC restrictions, are there any other factors taken into account when selecting specific routes. Can anyone shed any more light on this as it's driving my curiosity bonkers!

Cheers,,
NOC

Well, weather is most likely as you mentioned.

However, there are vast areas of the sky controlled/used by the military which are nofly zones for civil aircraft and these vary frequently according to exercises and many other reasons.

Most route changes are caused by this after weather etc.

We flew to MCO yesterday ex MAN and took a southern routing which is unusual and that due to the weather.

There is a good Wiki article on the North Atlantic Track system http://en.wikipedia.org/wiki/North_Atlantic_Tracks.

It doesn't account for random tracks, which are used to the Caribbean but does explain how it works.

Av8tor wrote:There is a good Wiki article on the North Atlantic Track system http://en.wikipedia.org/wiki/North_Atlantic_Tracks.

It doesn't account for random tracks, which are used to the Caribbean but does explain how it works.

Just had a quick read - very interesting article.

Much better than a plane simply heading in the direction it wants to go in !

Av8tor wrote:There is a good Wiki article on the North Atlantic Track system http://en.wikipedia.org/wiki/North_Atlantic_Tracks.

It doesn't account for random tracks, which are used to the Caribbean but does explain how it works.

Mmmm interesting, thanks for that

Regards,

NOC

As the wiki article says, the most significant factor in determining route is the jetstream. Riding the jetstream coming back from the US saves airlines vast sums of money, avoding it's winds head-on in the other way, likewise.

You may be surprised about how variable the jetstream can be in location, even over the course of a few days, and this accounts for the larger part of why you see so much variance. Take a look here for example.

Slinky has it on the nose: the flight planning system, LIDO, Airdata, Jepp will work out a mininimum time track (MTT). That is why when you look at the route on the Skyshow you may wonder "Why on earth are we going so far north / south". Essentially the tailwinds are optimised, hence a longer ground distance will take less time. Bit of a bummer if you have paid for UC only to find it's 5 hrs 30 back from NYC!

If I can hve an email I can send the detail in a PDF It wont copy and paste here.

As others have said its to do with the jetstreams.

However I think it must be a pretty fine line between the straight across route (ie: Going over Bermuda and then in over the Space Coast of Florida) when compared to go around over Canada and down the Eastern Seaboard.

Is it the case that it saves time to go via the Eastern Seaboard 90% of the time on a MCO or TPA (if your BA) but doesnt if your going into MIA? Only reason I say is that everytime I go into MIA we go straight across but yet 90% of the time into MCO its an Eastern Seaboard job....seems odd when they are relatively so close!

Hopefully this should get you the manual.

There is also the consideration of suitable diversion airports. It will take time for VS to get ETOPS180 so the new A333s may be forced to take longer routes.

As Neil mentioned we took the Azores/Bermuda route on Friday - jetstream right up the east coast with some severe turbulence. We were due to go North but managed to get last-minute clearance for the southerly route - nice earlier arrival.

Jeppeson will show the routes for the day.
The "North Atlantic High Lvl Sig." EB & WB in the centre of the page are the links to check