A study has been conducted to design an auxiliary flotation/stability system for the CH-53E helicopter which will keep the aircraft upright and afloat (with the cabin flooded) long enough to allow the evacuation of a full complement of combat troops. Configurations were made to be compatible with the proposed MH-53E helicopter and MCM equipment as well. The study showed that inflatable flotation bags provided the best design solution. Three such systems were designed in detail, one each for sea states 2, 4, and 5. Increasing system capability from sea state 2 to 5 results in only a slight increase in cost. The final systems should have acceptable reliability and maintainability characteristics, minimal impact on performance, and only cause a small weight penalty. In addition, a 1/10 Froude scaled model of the CH-53E and the auxiliary flotation systems has been designed and constructed. This model will be provided to the U.S. Navy for hydrodynamic testing.