Why are different routes flown between the the same pair of airports?

On two of my trips (same airline, same kind of plane 777), I noticed that the airplane took very different routes (from New York to UAE).

1st Trip in 2012 (blue): Duration 11h 30m

2nd Trip in 2013 (green): Duration 13h 00m

I know that the blue line is the shorter distance, and probably also because of jet streams, it took lesser time. But why a plane would take this green route, even not considering jet streams?

Since I am not an important person, I could not ask the captain of the plane this question at the end of journey.

P.S.: I observed the flight paths on the entertainment system this airline has for all passengers.

• Since I am not an important person, I could not ask the captain of the plane this question at the end of journey - Actually, I don't think a pilot would mind you asking them this. Dec 28 '13 at 4:57
• That might be correct, but approaching the pilot would be hard.
– Farhan
Dec 28 '13 at 14:19
• @Lnafziger thats when you find the expat FO and bug him instead Feb 19 '15 at 15:54
• @casey "bug" him... "BUG" him. I read that as "mug" him, and though that was and interesting way of extracting flight information... Feb 19 '15 at 16:21
• It can be a matter of jetstreams, weather or that the pilot wanted to avoid part of the airspace due to sector taxes and/or restriction. @MarkyMark that is what it may seem, but you must account that the Earth is not a plane and orthodromic routes are shorter than lexodromic ones. Jun 5 '15 at 11:17

Lots of reasons are possible, ranging from winds to other issues. In this case I'm willing to bet that the first flight was based on the most efficient routing to take advantage of tailwinds en route and that the second was avoiding Syrian and Turkish air space because of the political issues there earlier this year.

• Thanks. Political reasons might be a cause but the second trip (green) was in last month, and on my way back, the plane followed the blue route.
– Farhan
Dec 28 '13 at 14:22
• Regardless, I think the most efficient route may not be necessarily be fastest.
– Farhan
Dec 28 '13 at 14:23

Additionally to the answer of user241, countries have different route charges that may influence the airlines in their cost trade-off to take different routes. Route charges may be negotiated between airlines and countries, leading to different routes by different airlines.