Airworthiness Directives; Dowty Propellers Type R321/4-82-F/8, R324/4-82-F/9, R333/4-82-F/12, and R334/4-82-F/13 Propeller Assemblies

Özet

We are revising an existing airworthiness directive (AD) for the products listed above. That AD currently requires initial and repetitive ultrasonic inspections of propeller hubs, part number (P/N) 660709201. This new AD requires introducing a new hub assembly P/N as an optional terminating action to the repetitive hub inspections. This AD was prompted by the need to introduce an optional terminating action for the repetitive inspections. We are issuing this AD to prevent propeller hub failure due to cracks in the hub, which could result in loss of control of the airplane.