V-22 FLIGHT TEST LOADS ANALYSIS

V-22 Engineering and Manufacturing Development (EMD) design loads analysis has relied heavily on existing V-22 Full Scale Development (FSD) and ongoing Risk-Reduction flight test data. The V-22 design requirements represent a significant technological advancement leading to new challenges in both analysis and design. Two components of the V-22 which have been especially challenging in terms of loads analysis have been the rotor system and empennage. The proprotor is required to operate both as a helicopter rotor and as a propeller. This requires rotor loads analysis at very high thrust coefficients with significant rotor stall in rotary-wing mode and at very high forw ard speeds in airplane mode. The methods used to predict EMD rotor design loads are presented, and the predicted loads are compared to existing flight test data. The empennage is subjected to highly complicated wake effects due to the complex geometry of the aircraft especially in high-speed stall conditions with large control inputs. The test aircraft are instrumented for calibrated loads (internal shears and moments) at several critical locations on the airframe. Analysis of these calibrated loads has resulted in improvements to the aerodynamic model in the Generic Tiltrotor (GTR) flight simulation program leading to improved loads predictions. These improvements are presented.