Airworthiness Directive · Amendment 39-21434 · Main rotor mast inner race rings
Airbus Helicopters
This AD applies to all Airbus Helicopters, certificated in any category, as identified in paragraphs (c)(1) through (3) of this AD.
(1) Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, and AS350D helicopters.
(2) Model AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters.
(3) Model EC130 B4 and EC130 T2 helicopters.
The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, and AS350D helicopters; Model AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters; and Model EC130 B4 and EC130 T2 helicopters. This AD requires a one-time inspection to verify the presence and correct installation of the main rotor mast (MRM) upper bearing retaining rings, a repetitive inspection of the sealant bead on the MRM for damage, and corrective actions if necessary. This AD was prompted by a report of a missing retaining ring of the inner race of the MRM upper bearing. 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) For the purposes of this AD, an affected part is any MRM having part number (P/N) 350A37-1290-XX (where XX can be any numerical combination) and a serial number as listed in Airbus Helicopters Alert Service Bulletin AS350-62.00.42, Revision 0, dated September 17, 2018; Airbus Helicopters Alert Service Bulletin AS355-62.00.37, Revision 0, dated September 17, 2018; or Airbus Helicopters Alert Service Bulletin EC130-62A017, Revision 0, dated September 17, 2018, as applicable to your model helicopter, unless the upper bearing inner race retaining rings are verified to be installed correctly as specified in the inspection required in paragraph (i)(1) of this AD.
(2) For the purposes of this AD, a Group 1 helicopter is one on which an affected part is installed.
(3) For the purposes of this AD, a Group 2 helicopter is one on which an affected part is not installed.
(1) For Group 1 helicopters, within the compliance time specified in Figure 1 to paragraph (h) of this AD, and, thereafter, at intervals not to exceed 165 hours time-in-service (TIS): Inspect the MRM upper bearing sealant bead for damage in accordance with section 3.B.2.a of the Accomplishment Instructions of Airbus Helicopters Alert Service Bulletin AS350-62.00.42, Revision 0, dated September 17, 2018; Airbus Helicopters Alert Service Bulletin AS355-62.00.37, Revision 0, dated September 17, 2018; or Airbus Helicopters Alert Service Bulletin EC130-62A017, Revision 0, dated September 17, 2018, as applicable to your model helicopter, except you are not required to discard the plastic clamps (Item vv). For the purposes of this inspection, damage may be indicated by flaws, cracks, folds, separation, or absence of the sealant bead.
Note 1 to paragraph (h)(1): Unless specified otherwise, the hours TIS specified in figure 1 to paragraph (h) of this AD are those accumulated on the effective date of this AD by the helicopter since first flight.
(2) If, during any inspection of the MRM upper bearing sealant bead as required by paragraph (h)(1) of this AD, there is damage, before further flight, inspect the installation of the MRM upper bearing inner race retaining rings for discrepancies in accordance with paragraph (i)(1) of this AD.
(1) For Group 1 Helicopters: Within 660 hours TIS or 6 months, whichever occurs first after the effective date of this AD: Inspect the installation of the MRM upper bearing inner race retaining rings for discrepancies in accordance with the Accomplishment Instructions of section 3.B.2.b of Airbus Helicopters Alert Service Bulletin AS350 62.00.42, Revision 0, dated September 17, 2018; Airbus Helicopters Alert Service Bulletin AS355-62.00.37, Revision 0, dated September 17, 2018; or Airbus Helicopters Alert Service Bulletin EC130-62A017, Revision 0, dated September 17, 2018, as applicable to your model helicopter, except you are not required to discard the plastic clamps (Item vv). For the purposes of this inspection, discrepancies may be indicated by incorrect positioning or missing rings.
(2) If, during the inspection required by paragraph (i)(1) of this AD there are any discrepancies, before further flight, remove the affected part, inspect the MRM inner race for degradation, and replace the retaining rings in accordance with the Accomplishment Instructions of section 3.B.2.c of Airbus Helicopters Alert Service Bulletin AS350 62.00.42, Revision 0, dated September 17, 2018; Airbus Helicopters Alert Service Bulletin AS355-62.00.37, Revision 0, dated September 17, 2018; or Airbus Helicopters Alert Service Bulletin EC130-62A017, Revision 0, dated September 17, 2018, as applicable to you model helicopter, except you are not required to return parts to Airbus Helicopters. For the purposes of this inspection, degradation is indicated by damage to the retaining rings (including but not limited to cracks, scratches, and gouges), deterioration, or wear.
(3) If, during the inspection of the MRM inner race, as required by paragraph (i)(2) of this AD, there is any degradation, before next flight, repair or replace the MRM.
Verification on a helicopter of correct installation of the MRM upper bearing inner race retaining rings, as required by paragraph (i)(1) of this AD, or corrective action on a helicopter, as specified in paragraphs (h)(2), (i)(2), or (i)(3) of this AD, as applicable, constitute terminating action for the repetitive inspections required by paragraph (h)(1) of this AD for that helicopter.
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.
