Airworthiness Directive · Amendment 39-17113 · Tail rotor head
Eurocopter Deutschland GmbH Helicopters
This AD applies to Eurocopter Deutschland GmbH (ECD) Model MBB-BK 117 A-1, MBB-BK 117 A-3, MBB-BK 117 A-4, MBB-BK 117 B-1, MBB-BK 117 B-2, MBB-BK 117 C-1, MBB-BK 117 C-2, and BO-105LS A-3 helicopters, with a tail rotor pitch link (pitch link) part number (P/N) 117-31821, 117-31822, or B642M1018101 with a serial number listed in Appendix 1 of Able Engineering & Component Services (Able) Alert Service Bulletin (ASB) No. 2012-001, Revision IR, dated March 7, 2012, installed, certificated in any category.
We are adopting a new airworthiness directive (AD) for Eurocopter Deutschland GmbH (ECD) Model MBB-BK 117 (all versions) and BO-105LS A-3 helicopters. This AD requires inspecting the tail rotor pitch link spherical bearing for proper swaging. This AD is prompted by a report of a tail rotor pitch link with a spherical bearing that had migrated out of the bearing bore. The actions specified by this AD are intended to prevent failure of the tail rotor pitch link and subsequent 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.
For pitch links installed within the last 10 hours time-in-service (TIS), before further flight; for all other affected pitch links, within the next 10 hours TIS:
(1) Remove the pitch link.
(2) Clean the area around the spherical bearings and pitch link bearing bore chamfer.
(3) Apply axial hand pressure to the faces of both spherical bearings as shown in Figure 1 to Paragraph (e) of this AD.
(4) Using an 8X or higher power magnifying glass, inspect the boundaries between the bearing and the bearing bore chamfer surface. Determine that the bearings have been completely swaged and there is no gap between the edge of the bearing and the chamfer as shown in Figure 2 to Paragraph (e) of this AD.
(5) If a bearing is not completely swaged or there is a gap between the edge of the bearing and the chamfer, as shown in Figure 3 to Paragraph (e) of this AD, replace the pitch link with an airworthy pitch link.
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.
