There was a topic on this in the bugs forum, I think. You have to replace the seats of the aircraft because of the bug. And also, there was no way to fix it while the game is running (according to Sami).
YES there is a way to fix it.Just change the seating to fewer seats.put all standard and it will be fine.
That's weird.. should have worked fine. Maybe post it in the bug forum (preferably in the topic I refered to earlier on)
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