Flight Path Selections

I’m not a pilot but I enjoy watching the planes and trying to figure out where they are going.

To any pilots out there, how is the decision made regarding what route to fly (I’m talking about the long haul flight as opposed to shorter flights)?

For example, the following two flights went over my head (YYZ) this morning, both KIAD - RJAA:

ANA1 (777-300ER) took a flight path that took it over Alaska

UAL803 (777-200) took a ‘polar’ flight path

The flights left IAD about an hour apart, they are both a similar type of aircraft and yet they took completely different flight plans.

Thanks in advance,

Many moons ago, I used to work weight and balance for NH, when they still flew B744’s on this route. FOR the most part this has been their preferred route between IAD-NRT. The ONLY thing I can think that seperates the 2 routes is the winds aloft, and the space of the flights crossing that airspace. Keep in mind, that the JL, NH flights from JFK also depart around this time, and it could be space on the routes with those birds.

flightaware.com/live/flight/ANA9 NH9 KJFK-RJAA takes NCA24 across…like the UA out of IAD.

flightaware.com/live/flight/JAL5 JL5 KJFK-RJAA takes NCA30 like the NH out of IAD.

Part of this equation is the work required to get approval for polar routings. There is a very detailed set of requirements for airlines wanting to use these routes.

boeing.com/commercial/aeroma … story.html

Very interesting, thank you for the 411 sir!