Airworthiness Directive · Amendment 39-17245 · Fuselage main, attach fittings
Sikorsky Aircraft Corporation Helicopters
This AD applies to Sikorsky Aircraft Corporation (Sikorsky) Model S-92A helicopters, with a tail rotor (T/R) pylon, part number (P/N) 92000-06102-041, certificated in any category.
We are adopting a new airworthiness directive (AD) for the Sikorsky Aircraft Corporation (Sikorsky) Model S-92A helicopters. This AD requires inspecting the tail rotor (T/R) pylon for a loose or missing fastener, a crack, damage, or corrosion and adding an internal doubler to the aft shear deck tunnel assembly. This AD was prompted by the discovery of cracks in T/R pylons. The actions are intended to detect a loose or missing fastener, a crack, damage, or corrosion on the T/R pylon and, if present, to repair the T/R pylon and install a doubler on the aft shear deck tunnel assembly or to replace the T/R pylon and install a doubler on the aft shear deck tunnel assembly. The actions are intended to prevent failure of the T/R pylon or other T/R components, which could lead to the loss of control of the helicopter.
You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.
(1) For helicopters with 500 or more hours time-in-service (TIS), within 25 hours TIS and thereafter at intervals not to exceed 10 hours TIS, inspect each T/R pylon for a crack, damage, corrosion, or a loose or missing fastener in accordance with the Accomplishment Instructions, paragraph 3.A.(4)(a) through paragraph 3.A.(4)(f), and referring to Figure 1 of Sikorsky Alert Service Bulletin (ASB) No. 92-53-001, dated June 23, 2008, except that you are not required to contact Sikorsky Customer Service Engineering per paragraph 3.A.(4)(c) 1 of ASB 92-53-001, dated June 23, 2008.
(2) If there is a crack, damage, corrosion, or a loose or missing fastener, before further flight, either:
(i) If within allowable tolerances, repair each crack and each area of damage or corrosion and replace any loose or missing fastener; or
(ii) Replace the T/R pylon, (P/N) 92000-06102-041, with T/R pylon, P/N 92070-20058-042, as follows:
(A) Conduct the Total Indicated Run-out procedure on the No. 4 and No. 5 T/R drive shafts and remove the T/R pylon; and
(B) Install the doubler, P/N 92070-20087-101, as follows:
(1) For helicopters, serial numbers (S/Ns) 920006 through 920082, on the aft shear deck tunnel assembly, P/N 92204-05103-041 or -045, in accordance with the Accomplishment Instructions, paragraph 3.B.(1) through 3.B.(30) and while referring to Figures 1, 2, and 4 of Sikorsky ASB No. 92-53-004B, Revision B, dated June 21, 2011 (92-53-004B).
(2) For helicopters, S/Ns 920083 through 920124, on the aft shear deck tunnel assembly, P/N 92204-05103-043, in accordance with the Accomplishment Instructions, paragraph 3.C.(1) through 3.C.(21) and referring to Figures 3 and 4 of ASB 92-53-004B.
(3) If there is no crack in the T/R pylon, replace T/R pylon, P/N 92000-06102-041, with T/R pylon, P/N 92070-20058-042, and install doubler, P/N 92070-20087-101, on the aft shear deck tunnel assembly as specified in paragraphs (2)(ii)(A) through (2)(ii)(B) of this AD, according to the following:
(i) For a T/R pylon with 3,750 or more hours TIS, replace and install doubler within 12 months.
(ii) For a T/R pylon with 1,500 through 3,749 hours TIS, replace and install doubler within 24 months.
(iii) For a T/R pylon with 1,499 or less hours TIS, replace and install doubler within 36 months.
(4) Replacing T/R pylon, P/N 92000-06102-041, with T/R pylon, P/N 92070-20058-042, and installing internal tail cone doubler, P/N 92070-20087-101, on the aft shear deck tunnel assembly, constitutes terminating action for the requirements of this AD.
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
