Airworthiness Directive · Amendment 39-17868 · Main rotor brake
Agusta S.p.A. Helicopters
Superseded. A later AD replaced this one: AD 2020-18-19. Comply with the one in force.
This AD applies to Agusta S.p.A. (Agusta) Model AB412 and AB412EP helicopters with a rotor brake pinion, part number 412-040-301-101, installed, certificated in any category.
We are adopting a new airworthiness directive (AD) for Agusta S.p.A. (Agusta) Model AB412 and AB412EP helicopters with a certain rotor brake pinion installed. This AD requires inspecting the rotor brake pinion for a crack, and replacing it if there is a crack. This AD is prompted by a report of a rotor brake pinion failure. These actions are intended to detect a crack on the rotor brake pinion and prevent failure of the rotor brake pinion, which could lead to detachment of parts inside the transmission and subsequent loss of control of the helicopter.
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 100 hours time-in-service, magnetic particle inspect each rotor brake pinion for a crack. If there is a crack, before further flight, replace the rotor brake pinion.
