AD 2017-23-08 Airworthiness Directives; Agusta S.p.A. Helicopters

This AD supersedes AD 2014-24-02, Amendment 39-18035 (79 FR 70785, November 28, 2014).

(1) Within 5 hours time-in-service (TIS), and thereafter before the first flight of each day or at intervals not exceeding 24-clock hours, whichever occurs later: (i) Using a magnifying glass and a flashlight, visually inspect each bearing for wear of the bearing liner. Some examples of wear are shown in Figures 4 through 8 of Leonardo Helicopters Alert Bollettino Tecnico No. 139-392, Revision A, dated February 14, 2017 (BT 139-392). If there is any wear of the liner, before further flight, replace the bearing with bearing P/N 3G6230V00655 and install special nut P/N 3G6230A06851. Replacing the bearing with bearing P/N 3G6230V00655 constitutes terminating action for the remaining actions of this AD for the bearing. (ii) Inspect each bearing for movement. Refer to Figure 9 of BT 139-392. If the bearing moves freely out of its seat, before further flight, replace the rotating scissor attachment flange with flange P/N 3G6220A00633, replace the bearing with bearing P/N 3G6230V00655 and install special nut P/N 3G6230A06851. Replacing the bearing with bearing P/N 3G6230V00655 constitutes terminating action for the remaining actions of this AD for the bearing. (iii) Inspect the M/R rotating scissors for play and wear of each bearing, paying particular attention to the bearing staking condition, by manually moving the lower half scissor along the axis of the spherical bearing. Refer to Figure 1 of BT 139-392. If there is any play or wear beyond allowable limits, before further flight, replace the bearing with bearing P/N 3G6230V00655 and install special nut P/N 3G6230A06851. Replacing the bearing with bearing P/N 3G6230V00655 constitutes terminating action for the remaining actions of this AD for the bearing. (2) Within 100 hours TIS, replace and torque each lower half scissor nut with special nut P/N 3G6230A06851 to the M/R rotating scissor in accordance with the Compliance Instructions, Part II, steps 5.1 through 5.9 of BT 139-392, except you are not required to discard parts. (3) As of the effective date of this AD, do not install any M/R rotating scissors with a bearing P/N 3G6230V00654 installed.

(1) The Manager, Safety Management Section, FAA, may approve AMOCs for this AD. Send your proposal to: Matt Fuller, Senior Aviation Safety Engineer, Safety Management Section, Rotorcraft Standards Branch, FAA, 10101 Hillwood Pkwy, Fort Worth, TX 76177; telephone (817) 222-5110; email 9-ASW-FTW-AMOC-Requests@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.

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.

This AD defines the unsafe condition as excessive play of the bearing in the M/R rotating scissors. This condition could result in failure of the M/R rotating scissors and subsequent loss of control of the helicopter.