2020-02-17: Tail Rotor Blades

Adoption of the Amendment \n\n\n\tAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n0 1. The authority citation for part 39 continues to read as follows: \n\n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n\n\nSec. 39.13 (Amended) \n\n0 2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive (AD): \n\n2020-02-17 Sikorsky Aircraft Corporation: Amendment 39-21025; Docket No. FAA-2019-0663; Product Identifier 2018-SW-057-AD. \n\n(a) Effective Date \n\n\n\tThis AD is effective March 13, 2020. \n\n(b) Affected ADs \n\n\n\tNone. \n\n(c) Applicability \n\n\n\tThis AD applies to Model S-70, S-70A, S-70C, S-70C(M), and S- 70C(M1) helicopters, certificated in any category, with a tail rotor (T/R) blade part number 70101-31000 (all dash numbers) with a serial number (S/N) up to and including A009-08915. \n\tNote 1 to paragraph (c) of this AD: Each T/R blade is markedwith the S/N. \n\n(d) Subject \n\n\n\tJoint Aircraft System Component (JASC): 6410, Tail Rotor Blades. \n\n(e) Unsafe Condition \n\n\n\tThis AD was prompted by four incidents of disbonding between the T/R blade pitch horn and the torque tube. The FAA is issuing this AD to detect disbonding. The unsafe condition, if not addressed, could result in increased T/R vibrations, physical failure of the torque tube, and subsequent loss of control of the helicopter. \n\n(f) Compliance \n\n\n\tComply with this AD within the compliance times specified, unless already done. \n\n(g) T/R Blade Inspection \n\n\n\tBefore the first flight of each day: \n\t(1) Visually inspect each T/R blade for a crack, leading edge erosion, and trailing edge skin disbonding and separation, paying particular attention to the area from the midspan to the pitch control horn. If there is a crack, any leading edge erosion, trailing edge disbonding, or trailing edge separation, before further flight, replace the T/R blade with anairworthy part. \n\t(2) Tap test inspect each T/R blade for disbonding in the pitch horn to torque tube bond area. If there is any disbonding, before further flight, replace the T/R blade with an airworthy part. \n\n(h) Alternative Methods of Compliance (AMOCs) \n\n\n\t(1) The Manager, Boston ACO Branch, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the certification office, send it to the attention of the person identified in paragraph (i)(1) of this AD. \n\t(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. \n\n(i) Related Information \n\n\n\t(1) For more information about this AD, contact Kristopher Greer, Aviation Safety Engineer, Boston ACO Branch, Compliance & Airworthiness Division, FAA, 1200 District Avenue, Burlington, MA 01803; telephone 781-238-7799; email kristopher.greer@faa.gov. \n\t(2) For service information related to this AD, contact your local Sikorsky Field Representative or Sikorsky's Service Engineering Group at Sikorsky Aircraft Corporation, 124 Quarry Road, Trumbull, CT 06611; telephone 1-800-Winged-S or 203-416-4299; email wcs_cust_service_eng.gr-sik@lmco.com. Operators may also log on to the Sikorsky 360 website at https://www.sikorsky360.com. You may view the related service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy, Room 6N- 321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call 817-222-5110.