AD 2016-05-11 Airworthiness Directives; Sikorsky Aircraft Corporation

This AD becomes effective March 28, 2016.

(1) The Manager, Boston Aircraft Certification Office, FAA, may approve AMOCs for this AD. Send your proposal to: Blaine Williams, Aerospace Engineer, Boston Aircraft Certification Office, Engine & Propeller Directorate, 1200 District Avenue, Burlington, Massachusetts 01803; telephone (781) 238-7161; email blaine.williams@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: 6700, Rotorcraft Flight Control.

Within 5 hours time-in-service: (1) For each control input pushrod (pushrod) adjustable end, except for the upper deck quadrant pushrod: (i) Remove the safety cable and using finger pressure, inspect each jam nut for movement. If a jam nut moves with finger pressure, remove the pushrod assembly from service. (ii) Inspect to determine whether a 0.02 inch diameter safety wire can pass through the inspection hole. If the safety wire passes through the inspection hole, repair the pushrod in accordance with the Accomplishment Instructions, paragraphs C.(2)(b) through C.(2)(l) of Sikorsky S-92 Helicopter Alert Service Bulletin ASB 92-67-006, Revision A, dated February 19, 2016 (ASB), which is terminating action for that adjustable end. (iii) Where locking devices are used, inspect for correct engagement of serrations and keys of the locking device as shown in Figure 4 of the ASB. If a locking device is not correctly engaged, repair the locking device in accordance with the Accomplishment Instructions, paragraphs C.(3)(c) through C.(3)(f) of the ASB, which is terminating action for that adjustable end. (iv) Torque each jam nut using the torque values listed in Table 1 to paragraph (a) of this AD. Install the safety cable, making sure the right-hand threads have safety cable routed as shown in Figure 2 of the ASB, and the left-hand threads have safety cable routed as shown in Figure 3 of the ASB. (2) For the upper deck quadrant pushrod, determine whether there is any gap between the jam nut, locking device, and adjustable end. (i) If there is a gap, gain access to the pushrod, remove the safety cable, and using finger pressure, inspect the jam nut for movement. If the jam nut moves with finger pressure, remove the pushrod assembly from service. If the jam nut does not move, perform the actions in paragraphs (e)(1)(ii) through (e)(1)(iv) of this AD. (ii) If there is no gap, visually inspect the adjustable end for correct safety cable routing as shown in Figure 2 of the ASB, correct engagement of serrations and keys of the locking device as shown in Figure 4 of the ASB, and to determine whether any thread is visible in the inspection hole. If the safety cable is routed incorrectly, if the locking device is not correctly engaged, or if there is no thread in the inspection hole, gain access to the pushrod. Using finger pressure, inspect the jam nut for movement. If the jam nut moves with finger pressure, remove the pushrod assembly from service. If the jam nut does not move with finger pressure, perform the actions in paragraphs (e)(1)(ii) through (e)(1)(iv) of this AD.

This AD defines the unsafe condition as an incorrectly installed locking mechanism resulting in a loose jam nut. This condition, if not detected and corrected, could result in failure of the main rotor or tail rotor control pushrod, loss of main rotor or tail rotor flight control and consequent loss of helicopter control.