danwoodman00 From United States of America, joined Feb 2011, 23 posts, RR: 0 Posted (8 months 3 weeks 4 hours ago) and read 2525 times:
While thinking of a trip from Seattle to Tokyo, I looked at the flight plans for UA 875 and DL 155, both nonstop. UA875 is a 772, while DL155 just upgraded from a 763 to 744.
Using both Great Circle Mapper and Flight Aware, it looks like UA875 sticks to the "optimal" route. The DL flight, however, goes quite a long ways farther north -- following the pacific coastline up through Alaska, and coming down through the middle of the Kamchatka Peninsula on the other side.
I couldn't for the life of me figure out why Delta would have a *much* longer flight plan and duration? I was hoping someone here could help explain.
redtailmsp From United States of America, joined Feb 2004, 206 posts, RR: 2
Reply 1, posted (8 months 3 weeks 3 hours ago) and read 2317 times:
Could be any number of reasons. Great circle by itself does not necessarily mean fastest route, due to the position of the jetstreams. Going westbound, these winds are headwinds, so flying north of the jetstreams could be faster, and would probably be smoother too. Another issue recently has been some very active volcanoes along the Aleutian chain, so Delta could have been going to the expense of flying through Russian airspace over the Kamchatka Peninsula to stay away from any forecast volcanic ash. Normally, yes they would probably fly the most economic routing, but through an abundance of caution with regard to volcanic ash and turbulence, they will sometimes fly non optimal routings.
Roseflyer From United States of America, joined Feb 2004, 9355 posts, RR: 52
Reply 3, posted (8 months 3 weeks 1 hour ago) and read 2069 times:
It is always interesting to see airplanes choose different tracks. It could be as simple as timing on the more southern route was full at that time.
What I find fascinating is on the SEA-ICN route asiana nd Korean will often go on different sides of North Korea with Asian taking the northern route over Russia and china while Korean goes over Japan and approaches ICN from the south east.
If you have never designed an airplane part before, let the real designers do the work!
jetjack74 From United States of America, joined Jul 2003, 7377 posts, RR: 51
Reply 4, posted (8 months 3 weeks 1 hour ago) and read 1974 times:
Quoting danwoodman00 (Thread starter): While thinking of a trip from Seattle to Tokyo, I looked at the flight plans for UA 875 and DL 155, both nonstop. UA875 is a 772, while DL155 just upgraded from a 763 to 744.
B747400ERF From United Kingdom, joined Jun 2013, 220 posts, RR: 0
Reply 5, posted (8 months 2 weeks 6 days 22 hours ago) and read 1780 times:
Probably a combination of different weight, fuel burn and winds. My guess is the 777 was lighter and has a better fuel burn while the 744 was heavier and relied on going with the winds as much as possible to save costs.