Question for you flyers types...

[John Ranalletta]

I'm anxiously anticipating my second trip to Shanghai. I'm booked on UAL 835 in late Feb.

 

I've been tracking the in/outbound flights on Flightaware/Google earth. In the attached picture, the top line is a ruler line from ORD to PDG traced in Google earth. The second or middle line is the last outbound flight path which traces a similar line as that the flights that stopover at Narita.

 

The bottom line is the latest inbound flight path. It deviates substantially from the outbound and the most direct path (over Russia). Is that to optimize prevailing winds?

[Albert]

I believe you're correct John but there's enough professional pilots around here to give you a definitive answer.

 

An unrelated comment however, I'm not sure what time your flight will be but on one of my Asian flights we crossed Alaska on a clear afternoon. The mountain scenes were incredible. I think that was the only time (on numerous trans Pacific flights) I ever had a daylight crossing with clear weather. Enjoy.

[David]

John, Google "great circle path" for some interesting information as well.

 

Routes are planned based on:

 

--winds

--weather events

--fuel load

--emergency landing locations

--overfly permissions

[Mister Tee]

Typically, yes, commercial transatlantic and transpacific routes are planned to account for jet stream circulation. And, to some extent emergency stops.

[John Ranalletta]

Thanks. I figured Russia wouldn't be too fond of having 747 and 767 overflying the Kamchaka Peninsula, but I'd also figured a route transecting the Pacific put the flight a long way from a landing spot. The great circle path is helpful.

[upflying]

Thanks. I figured Russia wouldn't be too fond of having 747 and 767 overflying the Kamchaka Peninsula, but I'd also figured a route transecting the Pacific put the flight a long way from a landing spot. The great circle path is helpful.

You got that right. The USSR will shoot down civilian aircraft that cross into their airspace. I am sure that policy was pulled back a bit when they became Russia in 1991.

http://www.check-six.com/lib/Famous_Missing/KAL_Flight_007.htm

 

more here

http://en.wikipedia.org/wiki/Korean_Air_Lines_Flight_007

[bayoubengal]

David gave you good info:

 

Nearly always great circle routing.

 

Routes are planned based on:

 

--winds

--weather events

--fuel load

--emergency landing locations

--overfly permissions

 

Add: --Available airspace

 

Emergency Landing usually not a factor. Most ETOPS certs are good for most areas of the globe. Longest stretch on globe with no options is West coast to HI.

 

 

Thanks. I figured Russia wouldn't be too fond of having 747 and 767 overflying the Kamchaka Peninsula, but I'd also figured a route transecting the Pacific put the flight a long way from a landing spot. The great circle path is helpful.

 

Closest I ever came to being dead. I was on a spy mission near the peninsula with the Cobra Ball and the Cobra Eye in tow (I was the tanker) and had a pre-canned navigation package error. Came within 3 minutes of busting Russian airspace. We had Migs all over us. It would have been "the target is destroyed"... Fortunately we put our radar on ground paint (good technique when operating in sensitive areas...) momentarily and saw the coastline.

[bayoubengal]

The middle line looks to me is simply avoiding Russian airspace. The bottom route is a bit of a mystery to me.

[David]

Hutch, aren't some routes planned to be within a certain glide path of an airport in Iceland? Maybe I'm not remembering correctly.

[bayoubengal]

Hutch, aren't some routes planned to be within a certain glide path of an airport in Iceland? Maybe I'm not remembering correctly.

 

I have flown the North Atlantic extensively. But not in ETOPS aircrat. I've been in KC-135 and C-5 four-engine aircraft. 2 engine aircraft have different rules. Big majority of int'l flying is done with twins now. They do have to fly within a certain divert time to acceptable alternates. Not for engine out glide though. For single engine divert. I can tell you more next spring. I will be coming off my military leave and going to 767 or 777 back at Delta and going thru international ops training.

[David]

I'm jealous!