AD 2015-23-01 Airworthiness Directives; Sikorsky Aircraft Corporation (Type Certificate Previously Held by Schweizer Aircraft Corporation)

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

This AD becomes effective December 15, 2015.

(1) The Manager, New York Aircraft Certification Office, 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.

Joint Aircraft Service Component (JASC) Code: 6500, Tail Rotor Drive.

(1)Within 100 hours time-in-service (TIS): (i) Inspect each T/R driveshaft splined fitting for a crack, a break, excessive wear, galling, spalling, chipping, corrosion, heat discoloration, and distortion by following the Accomplishment Instructions, paragraphs 3.B.(1) through 3.B.(2), of Sikorsky 269 Alert Service Bulletin (ASB) B-299.1 for Model 269A, 269A-1, 269B, 269C, and TH-55A helicopters; 269C-1 ASB C1B-036.1 for Model 269C-1 helicopters; or 269D ASB DB-041.1 for Model 269D helicopters, each Revision 1 and dated February 24, 2012. If there is a crack, a break, excessive wear, galling, spalling, chipping, corrosion, heat discoloration, or distortion on any T/R driveshaft splined fitting, before further flight, replace the affected splined fitting and the T/R driveshaft. (ii) If installed, inspect each T/R driveshaft grease fitting for looseness, presence of a check ball inside each fitting, and for proper operation and seating of each check ball. If any grease fitting is loose, missing a check ball, fails to properly operate, or if a check ball fails to seat, before further flight, replace the grease fitting. (iii) Lubricate each driveshaft fitting by following the Accomplishment Instructions, paragraph 3.B.(6), of Sikorsky 269 ASB B-299.1 for Model 269A, 269A-1, 269B, 269C, and TH-55A helicopters; 269C-1 ASB C1B-036.1 for Model 269C-1 helicopters; or 269D ASB DB-041.1 for Model 269D helicopters, each Revision 1 and dated February 24, 2012. (2) Within 100 hours TIS after the inspections required by paragraph (e)(1) of this AD, and thereafter at intervals not exceeding 100 hours TIS: (i) Remove the driveshaft from the gearbox and clean any grease from each end fitting. (ii) Inspect the driveshaft for straightness, a twist, and a scratch. If the driveshaft has any bends, twists, or scratches, before further flight, replace the driveshaft. (iii) Inspect the internal splines of each forward and aft fitting and each internal stop for wear. If there is any wear, before further flight, replace the fitting. (iv) Inspect the drive splines of each splined drive fitting for wear. If there is any wear, before further flight, replace the splined drive fitting. (v) Loosen the aft frame clamp and apply a torque of 750 to 1,000 inch-pounds to each main transmission aft pinion nut.

This AD defines the unsafe condition as insufficient lubrication of a tail rotor (T/R) driveshaft splined fitting. This condition could result in excessive wear of the T/R driveshaft splines, which could lead to failure of the T/R driveshaft and subsequent loss of control of the helicopter.