Don't trust the Captain! Is his story about faked 815 true?
Aircraft found in Sunda Trench off Bali, according to Google
Earth that's 4000+ miles (8 hours flight time) west of Fiji Island.
Remember pilot said they flew 6 hours northeast toward LAX
had problems and turned back but didn't make it to Fiji.
815 that far off course could be explained by a time/space issue
that duplicated the aircraft sending one to Sunda Trench, one to Island.
Would explain Hurley and Jack in different flashes needing to get back to island,
they don't feel right in "real world". If Ben or Widmore were planting 815 to divert attention
from Island, would they put it that far off course guaranteeing an investigation?
Just a wild thought.

I think that's why they had Frank recognizing that that was not really the pilot that was in the plane... to indicate that it was indeed a fake rather than some kind of duplicate.

I don't think we have to get too far out there. I am in the "faked crash site" staged by Widmore rather than Ben camp. Although the fact that Lupidas was supposed to pilot 815 adds an interesting wrinkle.

I am also a fan of alternate dimensions...