[glup]

Interesting to compare with ETOPS (good maps: gc.kls2.com) which governs how far away from acceptable alternate airports a commercial plane can be. It corresponds to safe flying time with a single functional engine. So a lot of the area in some of the larger Voronoi regions, especially in the Southern Hemisphere, is actually unreachable by any commercial flight from the closest airport.

[JoeMalt]

It's worth noting that ETOPS only applies to 2-engine aircraft; a 4-engine aircraft can travel outside the ETOPS-permitted areas as long as it has enough fuel.

[rimliu]

And ETOPS was one of the reason for the trijets. Just recently watched: https://www.youtube.com/watch?v=gxnptDPy47M about this.

[detaro]

Depends on the jurisdiction, the FAA applies the same rules to 4-engine aircraft that are carrying passengers now.

[glup]

e.g. http://boeing.mediaroom.com/2015-03-18-Boeing-747-8-Intercon...

[madeofpalk]

When people say "ETPOS" these days, it's understood that they're talking about the maximum distance an aircraft of any size can fly from an airport - various regulators still apply such restrictions on aircraft with more than two aircrafts.

[coin]

> is actually unreachable by any commercial flight from the closest airport.

ETOPS is for twin engines (T for twin). Those restrictions do not apply to 3 and 4 engine aircrafts.

[isostatic]

I thought it stood for "Engines turn or passengers swim"

I'm not sure I'd like to be on a plane 6 hours from an airport -- better hope you don't have any sudden medical requirements that would lead to a diversion!