Airworthiness Directive · Amendment 39-17204 · Tail rotor head
Eurocopter France Helicopters
Superseded. A later AD replaced this one: AD 2013-03-02. Comply with the one in force.
This AD applies to Eurocopter Model EC 155B, EC155B1, SA-365N1, AS-365N2 and AS 365 N3 helicopters, with a tail rotor hub (TRH) part number 365A33351100, 365A33351101, or 365A33351102 installed, certificated in any category.
We are adopting a new airworthiness directive (AD) for Eurocopter France (Eurocopter) Model EC 155B, EC155B1, SA-365N1, AS- 365N2 and AS 365 N3 helicopters to require visually inspecting the tail rotor hub (TRH) for a crack and removing the TRH if a crack exists. This AD is prompted by reports of cracks on two TRHs. These actions are intended to prevent the tail rotor from jamming, which could lead to reduced or loss of control of the helicopter.
You are responsible for performing each action required by this AD within the specified compliance time.
(1) Within 55 hours time-in-service (TIS), and thereafter at intervals not to exceed 55 hours TIS, using a light, visually inspect the TRH for a crack in the entire area shown as Area C of the TRH (a) in Figure 1 to paragraph (e)(1) of this AD. The inspection area is on the tail gearbox (TGB) side of the TRH. The TGB is shown as (c) in Figures 2 and 3 to paragraph (e)(1) of this AD. You must pay particular attention to the area around the screws, shown as (e) in Figure 3 to paragraph (e)(1) of this AD, and the TRH between the lower part of the TGB and its fairing, shown as (d) in Figures 2 and 3 to paragraph (e)(1) of this AD, using details D and E of Figure 3 to paragraph (e)(1) of this AD. You must turn the tail rotor by hand to inspect the entire Area C.
(2) If there is a crack on the TRH, remove the TRH from service.
