At first I thought it was like in Inception, train riding through unexpectedly, but no, just a normal, day-to-day occurrence.
"He smiles. The plane is gone, finally free of the island. Jack Shephard has done what he came to this place to do. He has found his purpose. He has found love. And been loved. And he has finally found a way to love himself. The bamboo sways across the blue sky. And Jack Shephard's eye closes one final time. He is gone."