Flight evaluation of the Integrated Inertial Sensor Assembly (IISA) on a helicopter

After successful flight test evaluation of the integrated inertial sensor assembly (IISA) on an F-15 aircraft, the system was installed onboard a Blackhawk helicopter at Wilmington Airport in Delaware. An overview of the flight test evaluation conducted on the Blackhawk is presented. It is concluded that all program objectives were successfully demonstrated and proved that the IISA system can be used for helicopter applications. The IISA Helicopter Demonstration Program consisted of two phases. During the first phase, vibration data were obtained to quantify the helicopter´s vibration environment. Based on these data, IISA´s digital flight control filters were modified for flight control signal quality evaluations during the second phase. During the flight tests, no evidence of body bending modes or local structural vibration degrading IISA´s performance was found. The flight test data indicate that IISA´s flight control signals have the necessary dynamic range to satisfy future helicopter fly-by-wire flight control systems. IISA´s redundancy management software worked flawlessly during the insertion of hardover failures. From the standpoint of flight safety IISA exhibits full QUAD redundancy