Airworthiness Directives; Mitsubishi Heavy Industries MU-2B Series Airplanes

The FAA adopts a new airworthiness directive (AD) for all Mitsubishi Heavy Industries (MHI) MU-2B series airplanes. This AD requires you to incorporate power assurance charts into the Limitations Section of the Airplane Flight Manual (AFM), inspect the engine torque indication system, and recalibrate the torque pressure transducers as required. This AD results from a recent safety evaluation that used a data-driven approach to analyze the design, operation, and maintenance of the MU-2B series airplanes in order to determine their safety and define what steps, if any, are necessary for their safe operation. Part of that evaluation was the identification of unsafe conditions that exist or could develop on the affected type design airplanes. We are issuing this AD to detect and correct torque transducers that are out of calibration. The above issue, if uncorrected, could result in degraded performance and poor handling qualities with consequent loss of control of the airplane in certain situations.