Summary
The FAA proposes to revise an earlier proposed airworthiness directive (AD) that applies to all Mitsubishi Heavy Industries MU-2B series airplanes. The earlier NPRM would have required you to do the following: Remove and visually inspect the wing attach barrel nuts, bolts, and retainers for cracks, corrosion, and fractures; replace any cracked, corroded, or fractured parts; inspect reusable wing attach barrel nuts and bolts for deformation and irregularities in the threads; replace any deformed or irregular parts; and install new or reusable parts and torque to the correct value. The earlier NPRM resulted from a recent safety evaluation that used a data-driven approach to evaluate 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. This proposed AD would retain the actions from the earlier NPRM, add airplanes to the applicability, revise the serial numbers of the affected airplanes, and update the manufacturer's contact information. This proposed AD results from the manufacturer revising the service information to include two additional airplane models. Since these actions impose an additional burden over that proposed in the NPRM, we are reopening the comment period to allow the public the chance to comment on these additional actions.