AD/DHC-8/15 Amdt 3 - MLG Actuator Support Bracket and Bolts (Cth)

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

Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes

AD/DHC-8/15 Amdt 3

MLG Actuator Support Bracket and Bolts 11/95

Applicability: Model DHC-8 Series 100 and 300, with serial numbers 3 through 400, but not including 391.

Requirement: Action in accordance with the technical requirements of Transport Canada AD CF- 91-25R2.

Note: de Havilland SB 8-54-27 and SB 8-54-34 refer.

Compliance: As specified in the Requirement Document, with a revised compliance of 12 December 1995 for paragraph 3 of the Requirement Document for additional aircraft affected by this amendment of the Directive.

The compliance of the previous issue of this Directive remains unchanged with an exception as stated in the compliance statement. This Amendment is effective from 12 October 1995.

Background: An incident occurred where all hydraulic power was lost in-flight when a MLG retract actuator support bracket bolt failed. This occurrence allowed unrestricted actuator movement which resulted in damage to adjacent hydraulic lines.

Amendment 1 required specific torque checks on the bolts, and a non-destructive test on the support bracket if bolt looseness is detected.

Amendment 2 required terminating action in lieu of the on-going repetitive inspections.

Amendment 3 is issued in response to a revision of the Requirement Document, which mandates compliance with Revision A of Service Bulletin 8-54-34 that has new requirements added for a re-torque of the fasteners of the retraction actuator fitting between 50 and 100 flights after incorporation of Modification 8/2049.