Tracking performance requirements for rotorcraft instrument approaches to reduced minima. Phase 1: Preliminary study

The ability to track approach guidance (position and speed) to a low decision height (50 feet) when performing a steep instrument approach (6 to 9 degrees) in a rotoreraft clearly has a profound effect on the success of the approach. This report describes a preliminary attempl to define approach tracking standards for such approaches and includes a systematic data base upon which such standards can be based. This data base was generated in a 'light experiment in which qualified rotorcraft certification test pilots evaluated the suitabilily of arriving at the decision height with various combinations of approach tracking error. The magnitude of tracking errors that are compatible with satisfactory pilot workload in the transition to hover and landing is well defined and tracking within these error bounds is clearly within the limits of current technology. The experiment was performed on the National Research Council of Canada's Bell 205 Airborne Simulator.