Development of a Composite Tail Rotor Blade for the MH-53E

A new all composite co-cured tail rotor blade was designed to meet MH-53E mission requirements of improved performance, unlimited replacement time, and damage tolerance. A comprehensive test program was conducted to qualify the new blade for service. Risk reduction fatigue tests identified the lowest risk design approach. Full scale fatigue tests, using specially developed methods and facilities, were conducted to demonstrate the required strength and damage tolerance characteristics. Crack initiation tests revealed the critical fatigue modes at root end, mid-span, and tip locations. These modes were then propagated to determine damage tolerance characteristics. Pre-flight whirl tests acquired stability, performance, acoustic, and endurance information. Flight test surveys verified that the new tail rotor blade meets design requirements. Demonstrated performance, strength, and damage tolerance characteristics fulfill all requirements of the MH-53E mission.