Airworthiness Directive · Amendment 39-21272 · Flight controls
Airbus SAS Airplanes
This AD applies to all Airbus SAS Model A350-941 and -1041 airplanes, certificated in any category.
The FAA is superseding Airworthiness Directive (AD) 2018-17- 05, which applied to all Airbus SAS Model A350-941 and -1041 airplanes. AD 2018-17-05 required a check of the insulation resistance of the direct drive solenoid valve (DDSOV) of each affected electro-hydrostatic actuator (EHA) and applicable corrective actions. Since the FAA issued AD 2018-17-05, it was determined that certain EHA part numbers can be modified and re- identified as specified in a European Union Aviation Safety Agency (EASA) AD, which could inadvertently remove certain part numbers from the applicability in other EHA-related ADs including AD 2018-17-05. This AD was prompted by reports of EHA units that were returned to the manufacturer with degraded insulation resistance in the DDSOV; investigation results revealed that moisture ingress, due to incorrect sealing application, had caused this degradation. This AD was also prompted by a report of a technical issue detected on EHAs installed on inboard ailerons and elevators, causing potential erroneous monitoring of those actuators. This AD requires a check of the insulation resistance of the DDSOV of each affected EHA and applicable corrective actions, and modification or replacement of certain EHAs; as specified in two EASA ADs, which are incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.
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 (EASA) AD 2020-0027R1, dated February 21, 2020 (“EASA AD 2020-0027R1”); and EASA AD 2019-0301, dated December 12, 2019 (“EASA AD 2019-0301”).
(1) Where EASA AD 2019-0301 and EASA AD 2020-0027R1 refer to their effective dates, this AD requires using the effective date of this AD.
(2) The “Remarks” section of EASA AD 2019-0301 and EASA AD 2020-0027R1 do not apply to this AD.
(3) Where EASA AD 2019-0301 requires the accomplishment of paragraphs (1) through (6), this AD requires only the accomplishment of paragraphs (5) and (6).
(4) Paragraph (6) of EASA AD 2020-0027R1 specifies to report insulation check results (e.g., results of the detailed inspection of the insulation resistance) to Airbus within a certain compliance time. For this AD, report inspection results at the applicable time specified in paragraph (h)(4)(i) or (ii) of this AD.
(i) If the insulation check was done on or after the effective date of this AD: Submit the report within 30 days after the insulation check.
(ii) If the insulation check was done before the effective date of this AD: Submit the report within 30 days after the effective date of this AD.
(5) EASA AD 2020-0027R1 includes a definition for “affected EHA” that specifies “as listed by serial number in the applicable SB.” All serial numbers listed in the “applicable SB” are included in the definition of “affected EHA” regardless of the associated part numbers that are also listed in the “applicable SB.”
(6) For any service information referenced in EASA AD 2019-0301 that specifies to return parts to the manufacturer, that action is not required by this AD.
(7) Where any service information referenced in EASA AD 2019-0301 specifies rigging for testing, this AD allows rigging using Airbus Technical Adaptations 80602190/058/2020 and 80602190/059/2020 approved by the EASA Design Organization Approval (DOA) (EASA.21J.031).
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.
Aircraft
