The 747-400 Dreamlifter-Swing Tail Door Alignment and Latch Mechanism

One essential feature of the 787 production system is the 747-400 Large Cargo Freighter (LCF), also known as the Dreamlifter,([1]) and its ability to quickly and efficiently transport large components from global manufacturing locations to the final assembly site in Everett, Washington. This unique airplane has a tail section (Swing Tail) that opens to allow cargo loading. Quickly loading and unloading cargo is largely dependent on the reliable operation of the integral swing tail door alignment and latching systems. The swing tail door is approximately 23 feet horizontally by 29 feet vertically in size. The alignment and latching systems are required to function in a wide range of environmental conditions including temperature extremes and high winds. At the same time, these systems must ensure that flight loads are safely transmitted from the tail to the airplane fuselage without inducing undue fuselage preloads and without excessive play in the latching system. These requirements presented a developmental challenge that called for an innovative solution for adjustment of the latching and alignment mechanisms.