AD/BELL 212/59 - Tail Rotor Yoke (Cth)

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES

Bell Helicopter Textron 212 Series Helicopters

AD/BELL 212/59 Tail Rotor Yoke 8/98 DM

Applicability: Model 212 helicopters with tail rotor yoke assembly, part number (P/N) 212-011-702- all dash numbers, or P/N 212-010-704-all dash numbers, or P/N 212-010-744- all dash numbers installed.

Requirement: 1. Review all historical records of the helicopter and the tail rotor yoke assembly for any static or dynamic incident history that could have imposed an excessive bending load on the yoke. If such a history exists, comply with Requirement 2 before further flight.

Note 1: Examples of excessive bending loads include exposure to high wind gusts (such as those from rotor wash or prop blast), improper ground handling (in which the tail rotor blade has been used as a hand hold), improper feathering bearing removal (in which the yoke is not properly supported when pressing out bearings), a static ground strike of some type (such as being struck by a vehicle), or an incident in which a damaged tail rotor blade was replaced due to a blade strike. An overload may also occur dynamically during a power-on or power-off sudden stoppage incident or hard landing.

2. Remove the yoke assembly and replace it with a serviceable yoke assembly having zero hours time in service, or with a serviceable yoke assembly (regardless of time in service) that has passed an x-ray diffraction inspection in accordance with Bell Helicopter Textron, Inc. Alert Service Bulletin (ASB) 212-96-100, Revision A, dated 18 May 1998, or ASB 212-96-101 dated 3 September 1996, whichever is applicable. When the yoke assembly is replaced, for helicopters with a yoke assembly , P/N 212-011-702-all dash numbers, install a serviceable tail rotor flapping stop, P/N 212-011-713-103, and for helicopters with yoke assemblies, P/N 212-010-704-all dash numbers or P/N 212-010-744-all dash numbers, install an airworthy trunnion assembly, P/N 212-010-738-001. If any incident as described in Requirement 1 of this Directive occurs after 10 June 1998 and before compliance with this requirement, then compliance with Requirement 2 is required before further flight.