Hacker News Reader

Comment by robga | Hacker News Reader

This was a fun rabbit hole to go down, with the ETOPS [1] hint.

I enjoyed the history of ETOPS-138 [0]. ETOPS-120 leaves some small triangles of the Atlantic inaccessible, particularly if one emergency airfield is unavailable. A 15% increase to 138 minutes covers it.

Anecdotally, though, my experience as a commercial passenger feels like airlines fly almost directly over pacific islands rather than within X minutes of diversion. My memory may be anchored in bygone years.

[0] https://aviation.stackexchange.com/questions/30979/why-etops...

[1] https://en.m.wikipedia.org/wiki/ETOPS

View on HN

gcmap can map path with etops consideration http://www.gcmap.com/mapui

> pacific islands

Depending on the jet streams, the flight can take the great circle route [0] or taking advantage of the jet stream [1] and flying more southernly

[0] https://flightaware.com/live/flight/JAL6/history/20230108/02... [1] https://flightaware.com/live/flight/JAL6/history/20230105/02...

Even then, it didn't take the actual great circle route because Russia.

The Japan to Europe flights are even worse. The great circle route cuts west, straight across Russia [0]. These days, they fly east to the Bering Strait then more or less directly over the north pole [1] (though probably easier to see on great-circle: [2])

[0] http://www.gcmap.com/mapui?P=HND-FRA

[1] https://flightaware.com/live/flight/DLH717/history/20230109/...

[2] http://www.gcmap.com/mapui?P=HND-NUZAN-KUTAL-FRA

The direct route from FRA (Frankfurt Airport) to KUTAL (a navigational beacon on the Baring Sea in American airspace) passes within just 51 miles of the North Pole

Back in the Soviet era when USSR airspace was closed to most Western flights, planes couldn't do that route non stop from Europe, so had to stop over in Anchorage for refueling.

http://www.gcmap.com/mapui?P=BINP%2CFRA-KUTAL%0D%0A&MS=wls&D...

Need to find an excuse to go to Japan

That's pretty close.

Playing around, a theoretical NUE (Nuremberg) to KUTAL flight comes within 1 mile of the North Pole

Looking at FR24's tracks (which are suplemented by satellite updates now), they do seem to fly further south, presumably to benefit from winds

Well into the 24 hour polar night/day period though (depending on time of year)

I recommend the Wendover Productions Youtube video on ETOPS:

https://www.youtube.com/watch?v=HSxSgbNQi-g

I presume there must be an examption for Easter Island, which is so remote that they only allow one aircraft within a thousand miles https://en.wikipedia.org/wiki/Mataveri_International_Airport...

Reply on news.ycombinator.com