AD 2011-14-05 Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters

Models named: MD900. Read the applicability below — it usually turns on serial or part numbers too.

Model MD900 helicopters with main rotor lower hub assembly (lower hub), part number (P/N) 900R2101008-107, serial numbers (S/Ns) that begin with 5009, certificated in any category.

Within 100 hours time-in-service (TIS) or during the next annual inspection, whichever occurs first, unless done within the last 200 hours TIS: (1) Visually inspect the sides and bottom of the area between the arms for the centering bearing and the areas adjacent to the bushings of the lower hub assembly for a crack. If there is a crack, before further flight, replace the lower hub with an airworthy lower hub. (2) If the lower hub is not replaced as a result of the visual inspection required by paragraph (e)(1) of this AD, eddy current inspect the lower hub for a crack by following the Accomplishment Instructions, paragraphs 2.A(2) through 2.A.(10)., of MD Helicopters Inc. Service Bulletin SB900-117, dated January 14, 2011 (SB). If there is a crack, before further flight, replace the lower hub with an airworthy hub. (f) The eddy current inspection required by paragraph (e)(2) of this AD must be done by a Level II technician with ASNT-TC-1A, CEN EN 4179, MIL-STD-410, NAS410, or equivalent certification in eddy current inspections. The technician must have done an eddy current inspection in the last 12 months. Alternative Methods of Compliance (AMOCs) (g)(1) The Manager, Los Angeles Aircraft Certification Office (LAACO), 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 LAACO, send it to the attention of the person identified in the Additional Information section of this AD. (2) Before using any approved AMOC, we request that you notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. Additional Information (h) For more information about this AD, contact Eric Schrieber, Aviation Safety Engineer, FAA, Los Angeles Aircraft Certification Office, Airframe Branch, 3960 Paramount Blvd., Lakewood, California 90712-4137, telephone (562) 627-5348, fax (562) 627-5210. Material Incorporated by Reference (i)(1) Inspect the main rotor lower hub assembly for a crack by following the specified portions of MD Helicopter, Inc. Service Bulletin SB 900-117, dated January 14, 2011. The Director of the Federal Register approved the incorporation by reference of the service information, under 5 U.S.C. 552(a) and 1 CFR part 51. (2) For service information identified in this AD, contact MD Helicopters Inc., Attn: Customer Support Division, 4555 E. McDowell Rd., Mail Stop M615, Mesa, AZ 85215-9734, telephone 1-800-388-3378, fax 480-346-6813, or at http://www.mdhelicopters.com. (3) Copies may be inspected at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas, or at the National Archives and Records Administration (NARA). For information on the availability of this material at an NARA facility, call 202-741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

This amendment is prompted by the determination that a certain manufacturer had incorrectly inserted the flanged bushings into the lower hub bore. The actions specified by this AD are intended to detect a crack in the lower hub and prevent failure of the hub and subsequent loss of control of the helicopter.