The Army's new Advanced Attack Helicopter - the YAH-64 - achieves high performance with low cost and excellent maintainability. These desirable characteristics result from the Design Simplicity which has been inherent in the design approach since conception in 1972 and throughout the Phase 1 and Phase 2 development and flight test program. This inherent simplicity is the direct result of several fundamental decisions regarding basic configuration, plus intensive discipline at all levels of the design.