Airworthiness Directive · Amendment 39-19232 · Main rotor gearbox
Airbus Helicopters Deutschland GmbH (Type Certificate Previously Held by Eurocopter Deutschland GmbH)
This AD applies to Model EC135 P1, P2, P2+, P3, T1, T2, T2+, and T3 helicopters with a main transmission FS108 housing upper part, part number (P/N) 4649 301 034, 4649 301 067, or 4649 301 088 and a serial number listed in Table 1 of Airbus Helicopters Alert Service Bulletin EC135-63A-017, Revision 2, dated December 5, 2016 (ASB EC135-63A-017), certificated in any category.
We are superseding Airworthiness Directive (AD) 2013-16-14 for Eurocopter Deutschland GmbH (now Airbus Helicopters Deutschland GmbH) Model EC 135 P1, P2, P2+, T1, T2, and T2+ helicopters. AD 2013-16-14 required installing a washer in and modifying the main transmission filter housing upper part. Since we issued AD 2013-16-14, Airbus Helicopters Deutschland GmbH has extended the overhaul interval for the main transmission and determined that other models may have the same unsafe condition. This AD retains the requirements of AD 2013-16-14, adds models to the applicability, and revises the required compliance time for the modification. The actions of this AD are intended to correct an unsafe condition on these products.
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) Within 3 months, remove the oil filter element and install a corrugated washer, P/N 0630100377, in the middle of the filter housing of the housing upper part as depicted in Figure 2 of ASB EC135-63A-017.
(2) Within 5,150 hours time-in-service or at the next main transmission repair or overhaul, whichever occurs first, machine the main transmission housing upper part in accordance with Annex A of ZF Luftfahrttechnik GmbH Service Instruction No. EC135FS108-1659-1009, dated September 14, 2010.
(3) Do not install a main transmission upper part, P/N 4649 301 034, 4649 301 067, or 4649 301 088, on any helicopter unless it has been modified as required by paragraphs (f)(1) through (f)(2) 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.
