Airworthiness Directive · Amendment 39-21270 · Rotorcraft servo system
Airbus Helicopters
This AD applies to the following Airbus Helicopters model helicopters, certificated in any category:
(1) Model SA-365N, SA-365N1, AS-365N2, AS 365 N3, EC 155B, and EC155B1 helicopters with a main rotor (M/R) servo actuator part number (P/N) 704A44831074 (manufacturer part number (MP/N) SC8031), P/N 704A44831117 (MP/N SC8031-1), P/N 704A44831144 (MP/N SC8031-2), P/N 704A44831106 (MP/N SC8031A), P/N 704A44831097 (MP/N SC8032), P/N 704A44831118 (MP/N SC8032-1), P/N 704A44831145 (MP/N SC8032-2), P/N 704A44831127 (MP/N SC8033-1), P/N 704A44831146 (MP/N SC8033-2), P/N 704A44831128 (MP/N SC8034-1), P/N 704A44831147 (MP/N SC8034-2), P/N 704A44831149 (MP/N SC8037), or P/N 704A44831155 (MP/N SC8037-1) manufactured before July 25, 2019 or with an unknown date of manufacture, installed.
(2) Model AS350B3, AS355F, AS355F1, AS355F2, AS355N, AS355NP, EC130B4, and EC130T2 helicopters with an M/R servo actuator P/N 704A44831102 (MP/N SC8042) or P/N 704A44831103 (MP/N SC8043) manufactured before July 25, 2019 or with an unknown date of manufacture, installed.
The FAA is adopting a new airworthiness directive (AD) for certain Airbus Helicopters Model SA-365N, SA-365N1, AS-365N2, AS 365 N3, EC 155B, EC155B1, AS350B3, AS355F, AS355F1, AS355F2, AS355N, AS355NP, EC130B4, and EC130T2 helicopters. This AD requires inspecting the main rotor (M/R) servo actuators, and depending on the inspection results, replacing the affected part, applying a slippage mark, and reporting information. This AD was prompted by an incident of a sudden, strong nose-up attitude followed by intensive vibrations and increased loads on the flight controls during a cruise flight. The actions of this AD are intended to address 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 30 hours time-in-service, with any sealing compound on the lower ball end fitting link removed, determine if each M/R servo actuator is correctly installed by:
(i) Inspecting the link between the lower ball end fitting (f) and the actuator rod (a) for visible threads and play between the actuator rod (a) and the punched lockwasher (b) as depicted in Figures 1 and 2 of Airbus Helicopters Emergency Alert Service Bulletin (EASB) Nos. 67.00.17, 67A016, 67.00.77, 67.00.48, or 67A021, each Revision 0 and dated July 25, 2019 (EASB 67.00.17, 67A016, 67.00.77, 67.00.48, or 67A021), as applicable to your helicopter. If there is a visible thread or play, before further flight, replace the M/R servo actuator.
(ii) Inspecting for protrusion of the threaded shouldered bushing (c) from the punched lockwasher (b) as depicted in Figure 3 of EASB 67.00.17, 67A016, 67.00.77, 67.00.48, or 67A021, as applicable to your helicopter. If there is a protrusion, before further flight, replace the M/R servo actuator.
(iii) Inspecting the alignment between the punching of the punched lockwasher (b) and the stud of the lower ball end fitting (f) as depicted in Figure 4 of EASB 67.00.17, 67A016, 67.00.77, 67.00.48, or 67A021, as applicable to your helicopter. If there is misalignment, before further flight, replace the M/R servo actuator.
(2) After accomplishing paragraph (e)(1) of this AD, before further flight, apply a slippage mark from the actuator rod (a) (excluding the chamfered part of the rod) to the nut (e), including the punched lockwasher (b) and the lockwasher (d) as depicted in Figure 5 of EASB 67.00.17, 67A016, 67.00.77, 67.00.48, or 67A021, as applicable to your helicopter.
(3) If any parts were required to be replaced as a result of the inspections required by paragraph (e)(1) of this AD, within 10 days after completing the inspection, report the information in Appendix 1 to this AD by email to support.technical-hydraulics.ah@airbus.com.
(4) For Model SA-365N, SA-365N1, AS-365N2, AS 365 N3, EC 155B, and EC155B1 helicopters, as of the effective date of this AD, do not install an M/R servo actuator identified in paragraph (a)(1) of this AD on any helicopter, unless the actions required by paragraphs (e)(1) and (2) of this AD have been accomplished.
(5) For Model AS350B3, AS355F, AS355F1, AS355F2, AS355N, AS355NP, EC130B4, and EC130T2 helicopters, as of the effective date of this AD, do not install an M/R servo actuator identified in paragraph (a)(2) of this AD on any helicopter, unless the actions required by paragraphs (e)(1) and (2) of this AD have been accomplished.
A federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to a penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a currently valid OMB Control Number. The OMB Control Number for this information collection is 2120-0056. Public reporting for this collection of information is estimated to be approximately 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. All responses to this collection of information are mandatory. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to: Information Collection Clearance Officer, Federal Aviation Administration, 10101 Hillwood Parkway, Fort Worth, TX 76177-1524.
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.
