Airworthiness Directive · Amendment 39-16190 · Sikorsky Aircraft Corporation Model S-92A Helicopters
Sikorsky Aircraft Corporation Model S-92A Helicopters
Superseded. A later AD replaced this one: AD 2010-24-04. Comply with the one in force.
Model S-92A helicopters, with main gearbox (MGB) assembly, part number (P/N) 92351-15000-042 or -043, with MGB housing, P/N 92351-15110-042, -043, -044, or -045, installed, certificated in any category.
This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2009-23-51, which was sent previously to all known U.S. owners and operators of Sikorsky Aircraft Corporation (Sikorsky) Model S-92A helicopters by individual letters. This AD requires cleaning and inspecting each main gearbox (MGB) assembly mounting foot pad and rib for a crack and corrosion. If you do not find a crack, the AD requires applying a corrosion preventive compound. If you find a crack, the AD requires replacing the MGB before further flight. If you find corrosion, bubbled paint, or paint discoloration, the AD also requires you to repair the MGB before further flight. This amendment is prompted by reports of cracks in the MGB mounting foot pads and foot ribs. This condition, if not detected, could result in loss of the MGB and subsequent loss of control of the helicopter.
To prevent loss of an MGB and subsequent loss of control of the helicopter, do the following:
(a) Within 10 hours time-in-service (TIS), unless accomplished previously, and thereafter at intervals not to exceed 10 hours TIS, clean and inspect each MGB assembly mounting foot pad and rib for a crack and corrosion in the area depicted in Figure 1; as shown in the examples in Figures 2, 3, and 4; of Sikorsky Alert Service Bulletin No. 92-63-020, dated September 11, 2009 (ASB). If no crack is found, apply the corrosion preventive compound to each foot pad and rib area.
Note 1: When conducting a visual inspection, use a bright, non-LED light. (1) If you find a crack, replace the MGB before further flight. (2) If you find corrosion, bubbled paint, or paint discoloration, before further flight, repair the affected area.
Note 2: Following the ASB Accomplishment Instructions accomplishes the intent of this AD.
(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: Michael Schwetz, Aviation Safety Engineer, 12 New England Executive Park, Burlington, MA 01803, telephone (781) 238-7761, 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) Do the inspections by following the specified portions of Sikorsky Alert Service Bulletin No. 92-63-020, dated September 11, 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
