AD 2010-10-03 Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model S-92A Helicopters

Models named: S-92A. Read the applicability below — it usually turns on serial or part numbers too.

Model S-92A helicopters, with main gearbox (MGB) filter bowl assembly, part number (P/N) 92351-15802-101, installed, certificated in any category.

Required as indicated, unless done previously. To prevent failure of the MGB filter bowl assembly due to failure of the mounting studs or the filter bowl, loss of oil from the MGB, failure of the MGB, and subsequent loss of control of the helicopter, do the following: (a) Within 60 days: (1) Remove the MGB filter bowl assembly by following the Accomplishment Instructions, paragraphs 3.A. (1) through 3.A.(5), of Sikorsky Alert Service Bulletin No. 92-63-022A, dated December 18, 2009 (ASB). (2) Remove the primary filter element, P/N 70351-38801-102, from the MGB lube system filter and visually inspect it for damage as depicted in Figures 1, 2, and 3 of the ASB. If the primary filter element has “wavy” pleats, internal buckling, or indented dimples, before further flight, replace it with an airworthy filter element. (3) Visually inspect the secondary filter element, P/N 70351-38801-103, for damage as depicted in Figures 4 and 5 of the ASB. If the secondary filter element has “wavy” pleats or an elongated cup, before further flight, replace it with an airworthy filter element. (4) Replace the MGB lube system filter assembly mounting studs: (i) Remove the studs by following the Accomplishment Instructions, paragraphs 3.B.(1) through 3.B.(4) of the ASB. Visually inspect the tapped holes for any damage to the threads. Serrations on the entire counter bore (360 degrees) are acceptable. Serrations in the housing must be intact, and mating serrations on the lock ring must line up with serrations on the housing. Visually inspect the housing to determine that the housing threads are free from damage and corrosion. Visually inspect housing lockring counterbore to determine if the housing is airworthy. (ii) If you find damage or corrosion to the housing threads, the housing, or the lockring counterbore, stop work and contact Kirk Gustafson, Aviation Safety Engineer, Boston Aircraft Certification Office, Engine and Propeller Directorate, FAA, 12 New England Executive Park, Burlington, MA 01803, telephone (781) 238-7190, fax (781) 238-7170. (iii) If you do not find damage to the housing threads, the housing, or the lockring counterbore that requires repair, replace the mounting studs by following the Accomplishment Instructions, paragraphs 3.B.(7) through 3.B.(15) of the ASB. (5) Install an airworthy, two-piece MGB filter bowl assembly modification kit, P/N 92070-35005-011, as depicted in Figures 8 and 9 of the ASB and by following the Accomplishment Instructions, paragraphs 3.C.(1) through 3.C.(20), of the ASB. (b) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Contact the Manager, Boston Aircraft Certification Office, Attn: Kirk Gustafson, Aviation Safety Engineer, Boston Aircraft Certification Office, Engine and Propeller Directorate, FAA, 12 New England Executive Park, Burlington, MA 01803, telephone (781) 238-7190, fax (781) 238-7170, for information about previously approved alternative methods of compliance. (c) The Joint Aircraft System/Component (JASC) Code is 6320: Main Rotor Gearbox. (d) Inspecting and replacing the MGB filter bowl assembly shall be done by following the specified portions of Sikorsky Alert Service Bulletin No. 92-63-022A, dated December 18, 2009. The Director of the Federal Register approved this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Sikorsky Aircraft Corporation, Attn: Manager, Commercial Technical Support, mailstop s581a, 6900 Main Street, Stratford, CT, telephone (203) 383-4866, e-mail address tsslibrary@sikorsky.com , or at http://www.sikorsky.com . 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 NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. (e) This amendment becomes effective on June 21, 2010. Issued in Fort Worth, Texas, on April 27, 2010. Mark R. Schilling, Acting Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. 2010-11069 Filed 5-14-10; 8:45 am] BILLING CODE 4910-13-P