Airworthiness Directive · Amendment 39-23479 · Main rotor gearbox
Airbus Helicopters Deutschland GmbH (AHD) Helicopters
This AD applies to all Airbus Helicopters Deutschland GmbH (AHD) Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, EC135T3, and EC635T2+ helicopters.
Note 1 to paragraph (c): Helicopters with an EC135P3H designation are Model EC135P3 helicopters. Helicopters with an EC135T3H designation are Model EC135T3 helicopters.
The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Deutschland GmbH (AHD) Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, EC135T3, and EC635T2+ helicopters. This AD was prompted by a determination that in cases of loss of oil from the main gearbox (MGB), the low pressure caution or warning light might not activate. This AD requires revising the existing rotorcraft flight manual (RFM) for the helicopter by incorporating updated emergency, malfunction, and normal procedures. The FAA is issuing this AD to address the unsafe condition on these products.
(1) Except as specified in paragraph (h) of this AD: Comply with all required actions and compliance times specified in, and in accordance with European Union Aviation Safety Agency AD 2026-0080, dated April 17, 2026 (EASA AD 2026-0080).
(2) Insert the following language into the Normal section of the existing rotorcraft flight manual (RFM) for your helicopter: “WARNING: Pilots must vigilantly monitor the main gearbox oil pressures and temperatures. Main gearbox oil loss could occur without triggering cautions, warnings, or audio alerts. Catastrophic failure of the main gearbox could result in severe aircraft damage, injury, or death.”
(3) The owner/operator (pilot) holding at least a private pilot certificate may revise the existing RFM for the helicopter, as required by this AD, and must enter compliance into the helicopter maintenance records in accordance with 14 CFR 43.9(a) and 91.417(a)(2)(v). The record must be maintained as required by 14 CFR 91.417, 121.380, or 135.439.
(1) Where EASA AD 2026-0080 refers to its effective date, this AD requires using the effective date of this AD.
(2) Where EASA AD 2026-0080 refers to flight hours, this AD requires using hours time-in-service.
(3) Where paragraph (1) of EASA AD 2026-0080 specifies “implement the updated procedures, as defined in this AD,” this AD requires replacing that text with “amend the existing RFM for the helicopter by inserting a copy of the RFM TR [temporary revision] specified in EASA AD 2026-0080”.
(4) This AD does not adopt paragraph (2) or the “Remarks” section of EASA AD 2026-0080.
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.
