Helicopter Command Instrument Systems

Helicopter aerodynamics and ground electronic approach aids have significantly improved over the past few years. Today's helicopters are faster and more maneuverable and ground systems enable variable steep angle approaches. In order to keep abreast with airframe and electronic development, a serious Human Factors effort has been initiated to insure adequate displays to enable the pilot to accomplish the maneuvers that the airframe and ground systems are capable of producing. Specifically, the effort has concentrated on command instrument systems. Fixed wing aircraft have used command instrument systems, commonly known as flight directors, for many years. The direct application of the fixed wing systems to helicopters has proven inadequate, resulting in a command instrument system designed uniquely for helicopters. The importance of a command instrument system is twofold: (a) the increased emphasis on helicopter IFR flight and (b) the expanded flight envelope of helicopters in the steep angle approach regime. In both applications, the command instrument system improves flight path accuracy while reducing pilot workload. This enables the maximum utilization of the helicopter in the vertical plane for which it is best suited.