Thanks everyone.
I agree that the simple plan above to locate the plane does assume not many zig zags in the last 6 hours and it does not take account of a path needing to avoid radar.
However if you assume the plane goes fairly straight for the last six hours, covering say about 4000km from the Andaman sea, then there are only two final resting places on the red arcs/corridors.
They seem to be a northern one at 37N, 68E in northern Pakistan and a southern one at 25S, 91E about 2000km west of Perth.
The northern destination seems slightly more attractive but goes through Indian radar coverage.
The southern one seems a very sad place to end up.
Last edited by ana1936; 15th Mar 2014 at 12:22.
Reason: typo