Sensitivity Analysis of Helicopter IMC Decelerating Steep Approach and Landing Performance to Navigation System Parameters

This paper presents the results of a study to investigate, by means of a computer simulation, the performance sensitivity of helicopter IMC Decelerated Steep Approach and Landing (DSAL) operations as a function of navigation system parameters. A mathematical model representing, generically, a navigation system is formulated. The scenario simulated consists of a straight in helicopter approach to landing along a 6° glideslope. The deceleration magnitude chosen is .03g. The navigation model parameters are varied and the statistics of the total system errors (TSE) computed. These statistics show that the quantization of the estimated range rate, the bandwidth of the on-board digital filter and the noise in the range measurements are the critical navigation system parameters.