One of the key innovations in the 747X family was the creative use of previously unused overhead space above the ceiling of the passenger cabin. This computer-generated rendering depicts how the overhead space above the airplane's main deck might have been configured with passenger sleeping berths, changing rooms or reading rooms. The overhead space, would be accessed by a staircase from below, providing a higher level of privacy for premium-fare passengers. The space also could be used for crew-rest areas and meal-cart storage. Two versions had been planned, the 747X and the 747X Stretch.