AD 2013-03-04 Airworthiness Directives; Schweizer Aircraft Corporation

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

This AD becomes effective March 19, 2013.

Special flight permits may be issued in accordance with 14 CFR 21.197 and 21.199 provided that before operating the helicopter to a location to perform the actions in paragraphs (e)(1) through (e)(3) of this AD, a daily, pre-flight visual inspection is accomplished in accordance with paragraph (e)(1) of this AD.

(1) The Manager, NY ACO, FAA, may approve AMOCs for this AD. Send your proposal to: Stephen Kowalski, Aviation Safety Engineer, New York Aircraft Certification Office, Engine & Propeller Directorate, 1600 Stewart Ave., suite 410, Westbury, NY 11590; telephone (516) 228-7327; email stephen.kowalski@faa.gov. (2) For operations conducted under a 14 CFR part 119 operating certificate or under 14 CFR part 91, subpart K, we suggest that you notify your principal inspector, or lacking a principal inspector, the manager of the local flight standards district office or certificate holding district office before operating any aircraft complying with this AD through an AMOC.

(1) Before the first flight of each day, visually inspect the aft fuselage assembly in the area around the attachment point of the horizontal stabilizer, including the paint, for a crack. If there is a crack, remove the horizontal stabilizer and perform an interior inspection in accordance with Part II: Internal Inspection, paragraphs b. and c., of Schweizer Service Bulletin DB-018.3, dated December 13, 2007 (SB). (i) If there is a crack in the aft fuselage assembly clip, in the aft bulkhead, or in adjacent skins, repair the crack. Thereafter, at intervals not to exceed 200 hours time-in-service (TIS), remove the horizontal stabilizer and repeat the interior inspection in accordance with Part II: Internal Inspection, paragraphs b. and c., of the SB, or replace the aft fuselage assembly, P/N 269D3300-1,with an airworthy aft fuselage assembly, P/N 269D3300-35. (ii) If there is a crack in a longeron, tailboom tube collar or a forward stabilizer bulkhead, replace the aft fuselage assembly with an airworthy aft fuselage assembly, P/N 269D3300-35. (2) Within 100 hours TIS or three months, whichever occurs first: (i) Remove the horizontal stabilizer, clean the horizontal stabilizer mounting brackets, and inspect the mounting brackets for wear greater than 0.002-inch deep. If the bracket wear exceeds 0.002-inch deep, replace the mounting bracket with an airworthy mounting bracket. (ii) Modify the aft fuselage assembly by installing Inspection Panel kit P/N SA-269DK-035. (iii) Install doublers on the forward side of each mounting bracket in accordance with Part III-2, paragraphs e. through i., of the SB. (iv) Inspect the horizontal stabilizer forward and aft spars for wear in the mounting attachment areas. If the wear exceeds 0.002-inch deep, replace the spar with an airworthy spar. (v) Inspect for rivet interference between the rivet heads and skin on the top surface of the horizontal stabilizer and the tailboom stiffening Web near Station 232.4. If interference exists, replace with airworthy rivets. (vi) Install an airworthy horizontal stabilizer using 4 bolts, P/N NAS1304-4, and 4 washers, P/N AN960KD416 or NAS1149D0463K. (3) Removing aft fuselage assembly, P/N 269D3300-1, and replacing it with aft fuselage assembly, P/N 269D3300-35, is terminating action for the requirements of this AD.

This AD defines the unsafe condition as loose horizontal stabilizers and cracks in the stabilizer support structure for the extruded tailboom, which could result in separation of the horizontal stabilizer from the helicopter and subsequent loss of helicopter control.