AD/DO 328/25 - Propeller Control Unit Bearing

This Airworthiness Directive requires operators of Dornier 328‑100 aeroplanes fitted with Propeller Control Unit (PCU 1‑170A) P/N D‑1199‑2 (serial numbers up to and including PCU‑A‑EFS379) to inspect the PCU or maintenance records for incorporation of Hartzell Service Bulletin HD‑SB‑61‑012 and, if not incorporated, to carry out that SB. Compliance is mandatory within 30 days and the AD is effective 19 January 2006.

The stated purpose is to prevent premature bearing failure; operators and maintenance providers bear inspection, retrofit, documentation and downtime costs (Applicability; Requirement; Compliance; Background).