Airworthiness Directive · Amendment 39-17948 · Main rotor head
Airbus Helicopters Deutschland GmbH (Previously Eurocopter Deutschland GbmH) (Airbus Helicopters) Helicopters
This AD applies to Model EC135P1, EC135P2, EC135P2+, EC135T1, EC135T2, and EC135T2+ helicopters, with a main rotor hub (MRH) shaft, part number (P/N) L623M1006101, L623M1206101, L623M1006102, L623M1206102, L623M1006103, or L623M1206103 installed, certificated in any category.
We are superseding Airworthiness Directive (AD) 2012-10-53 for Eurocopter Deutschland GmbH (ECD) (now Airbus Helicopters) Model EC135P1, EC135P2, EC135P2+, EC135T1, EC135T2, and EC135T2+ helicopters. AD 2012-10-53 required, before further flight and at specified intervals, checking and inspecting the upper and lower main rotor hub (MRH) shaft flanges for a crack, and inspecting the lower hub-shaft flange bolt attachment areas for a crack. Since we issued AD 2012-10- 53, it has been determined that it is safe to increase the visual inspection intervals of the MRH shaft flanges from 10 hours time-in- service (TIS) to 50 hours TIS and remove the inspection of the lower MRH shaft flange bolt attachment areas. This new AD continues to require checking and inspecting the upper and lower MRH shaft flanges for a crack. These actions are intended to detect a crack on the MRH shaft flange, which if not corrected, could result in failure of the MRH 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.
(1) Before further flight, and thereafter at intervals not to exceed 6 hours time-in-service (TIS), check the MRH shaft lower flange and the visible area of the MRH shaft upper flange for a crack. Figures 1 and 2 to Paragraph (f)(1) of this AD are examples of cracks that have been discovered in the MRH shaft lower flange. The actions required by this paragraph may be performed by the owner/operator (pilot) holding at least a private pilot certificate, and must be entered into the aircraft records showing compliance with this AD in accordance with 14 CFR 43.9 (a)(1) through (4) and 14 CFR 91.417(a)(2)(v). The record must be maintained as required by 14 CFR 91.417, 121.380, or 135.439.
(2) For MRH shafts with 400 or more hours TIS, within 50 hours TIS, and thereafter at intervals not to exceed 50 hours TIS:
(i) Remove the rotor-hub cap.
(ii) Clean the upper and lower MRH shaft flange as depicted in Figure 2 of Eurocopter Alert Service Bulletin No. EC135-62A-029, Revision 7, dated October 22, 2012, and visually inspect for a crack.
(3) If there is a crack in the upper or lower MRH shaft flange, before further flight, replace that MRH shaft with an airworthy MRH shaft. Replacing the MRH shaft with an MRH shaft having a P/N listed in paragraph (a) of this AD does not constitute terminating action for the requirements of this AD.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
