Before listening to some Israeli Ban-happy Rov, I suggest you call your American Rov, the airplane is a Rshuas Hayachid, which is also sealed, even though tumah goes all the way up to the skies, it is sort of the same as a kohen walking in a cemetary with people surrounding him....
Also many ELAL flights going to Israel have a Meis on-board and it is not a halachic problem because of the way the do it, they worked it out with the Poskim