AD/JBK 117/14 - Tail Rotor Drive Long Shaft Hanger Bearing - Inspection of Fasteners (Cth)

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

Kawasaki BK 117 Series Helicopters

AD/JBK 117/14 Tail Rotor Drive Long Shaft Hanger Bearing - Inspection of Fasteners

Applicability: Kawasaki BK 117 Helicopters - all serial numbers.

5/99 TX

Requirement: Inspect the tail rotor drive long shaft hanger bearing fasteners for torque loading in accordance with the instructions in Kawasaki Service Bulletin No. KSB-117-148 dated 25 Feb 99. All inspection reports are to be forwarded to Kawasaki in the format shown in the Service Bulletin. Major defects discovered during satisfaction of this Directive are to be notified to Kawasaki Heavy Industries, Japan.

Note: JCAB Airworthiness Directive TCD-4975-99 dated 25 February 1999 refers.

Compliance: Before next flight after the effective date of this Directive.

This Airworthiness Directive becomes effective on 18 March 1999.

Background: Excessive worn out bolt holes have been found on the bearing support which secures the hanger bearing of the tail rotor drive long shaft. This situation is believed to have been brought about by the under torquing of the bolts during maintenance/assembly in service. This directive instructs inspection of the assembly for correct torque loading on the fasteners. In the event of fasteners being found under-torqued, the fasteners must be removed and the bolt hole measured for wear. Reporting provisions in accordance with the Kawasaki referenced service bulletin are mandatory.