USE OF SIMULATION FOR QUALIFICATION OF HELICOPTER EXTERNAL LOADS

This paper reports on two external load stability studies conducted by Sikorsky Aircraft, one for the CH-53E Super Stallion and another for the UH-60L BLACK HAWK. The focus of the paper is on the validation of frequency responses generated by Sikorsky’s Generalized Helicopter Flight Dynamic Simulation (GenHel) against an extensive set of flight test measurements. An overview of GenHel is presented followed by a summary of the CH-53E and UH-60L flight test programs. Correlation of GenHel predicted frequency responses and stability margins to those obtained from flight testing are then shown. These results indicate that GenHel is capable of reasonably accurate predictions of the stability margins of the coupled load / suspension / flight control / rotor / airframe system. The requirements for simulation fidelity to achieve this correlation are discussed together with a proposed plan for analytically qualifying external loads by simulation evaluation of their stability. Use of simulation to qualify external loads has a great potential to both reduce costs and increase safety.