Summary
We propose to adopt a new airworthiness directive (AD) for certain Turbomeca S.A. Astazou XIV B and H turboshaft engines. This proposed AD was prompted by a report of a crack on the 3rd stage turbine wheel. This proposed AD would require a one-time inspection of the front surface of the 3rd stage turbine for a groove. We are proposing this AD to prevent cracks in the 3rd stage turbine wheel, failure of the engine, in-flight shutdown, and loss of control of the helicopter.