Airworthiness Directive · Amendment 39-18318 · Cargo compartments
Agusta S.p.A. Helicopters
This AD applies to Model AB412 helicopters with a hydraulic external hoist part number BL10300-60 installed, certificated in any category.
We are adopting a new airworthiness directive (AD) for Agusta S.p.A. (Agusta) Model AB412 helicopters. This AD requires inspecting the filters installed on the pressure lines of utility hydraulic systems for metal particles. This AD is prompted by a report of a pump failure on the hydraulic external hoist caused by metal particles. These actions are intended to detect metal particles in the filter of the pressure line and prevent the pumps' failure, which could lead to a hoisting accident and injury to persons.
You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.
Within 10 hours time-in-service (TIS) and thereafter at intervals not to exceed 25 hours TIS:
(1) Inspect the hydraulic external hoist pressure line filter for metal particles.
(2) If there are any metal particles, before further flight, flush the utility hydraulic system, replace the pressure line pump, and replace the filter.
