Airworthiness Directive · Amendment 39-16130 · Sikorsky Aircraft Corporation (Sikorsky) Model S-92A Helicopters
Sikorsky Aircraft Corporation (Sikorsky) Model S-92A Helicopters
Model S-92A helicopters, serial numbers 920006 through 920109, certificated in any category.
This amendment adopts a new airworthiness directive (AD) for the Sikorsky Model S-92A helicopters. This action requires a one-time visual inspection of the main gearbox (MGB) lube system filter assembly for oil filter damage. This action also requires if either the primary or secondary oil filter is damaged, replacing both filters, all packings, and the studs before further flight. This AD also requires replacing the oil filter bowl within 30 days after replacing a damaged filter and a daily leak inspection for an oil leak (no oil leaks allowed) during that 30-day interim period. This amendment is prompted by three reports of damaged oil filters or packings resulting from installing the filter assembly with an oversized packing possibly because of incorrect part numbers in the maintenance manual. Based on a previous accident investigation, failure of the oil filter bowl or mounting studs can result in sudden and complete loss of oil from the MGB. The actions specified in this AD are intended to prevent complete loss of oil from the MGB, failure of the MGB, and subsequent loss of control of the helicopter.
To prevent complete loss of oil from the main gearbox (MGB), failure of the MGB, and subsequent loss of control of the helicopter, do the following:
(a) Within 7 days, inspect the MGB lube system filter assembly for damage to the primary and secondary oil filters by following the Accomplishment Instructions, paragraphs 3.A.(4) and through 3.A.(6) of Sikorsky Alert Service Bulletin (ASB) No. 92-63-018, dated July 1, 2009 (ASB No. 92-63-018). For purposes of this AD, “damage” is the presence of those conditions described in paragraphs 3.A.(5) and 3.A.(8) of the Accomplishment Instructions of ASB No. 92-63-018.
(b) If you find damage in the primary oil filter element (part number (P/N) 70351-38801-102) as follows: “wavy pleats” as depicted in Figure 1, internal buckling or a crack as depicted in Figure 2, or indented dimples as depicted in Figure 3 of ASB No. 92-63-018 or damage in the secondary oil filter element (P/N 70351-38801-103) as follows: “wavy pleats” as depicted in Figure 4 or an elongated cup as depicted in Figure 5 of ASB No. 92-63-018, replace both the primary and secondary filters, packings, and filter bowl mounting studs, service the transmission and perform a functional test before further flight by following the Accomplishment Instructions, paragraphs 3.C.(1) through 3.C.(23), of ASB No. 92-63-018, except this AD does not require you to return removed studs to HSI nor does it require you to contact the manufacturer. If you find damage in the tapped holes or in the MGB housing lockring counterbore, contact the Boston Aircraft Certification Office for an approved repair.
(c) If you find no damage in the primary or secondary oil filter element, before further flight, replace the packings, service the transmission, and perform a functional test by following the Accomplishment Instructions, paragraphs 3.B.(1) through 3.B.(4) of ASB No. 92-63-018.
(d) For those helicopters on which the primary or secondary oil filter element and filter bowl mounting studs were replaced as required by paragraph (b) of this AD:
(1) Before the first flight of each day until the oil filter bowl, P/N AAC367-16D2A, is replaced, inspect the MGB lube system filter assembly for any oil leak.
(2) Before further flight after any oil leak is detected as required by paragraph (d)(1) of this AD or within 30 days, whichever is earlier, replace the oil filter bowl.
Note: Sikorsky ASB No. 92-63-019, dated July 1, 2009, pertains to the subject of this AD.
(e) 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, FAA, ATTN: Kirk Gustafson, Aviation Safety Engineer, 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.
(f) The Joint Aircraft System/Component (JASC) Code is 6300: Main Rotor System.
(g) Inspecting and replacing the main gearbox lube system assembly parts shall be done by following the specified portions of Sikorsky Alert Service Bulletin (ASB) No. 92-63-018, dated July 1, 2009. The Director of the Federal Register approved this incorporation by reference under 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.
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.
Aircraft
