AD/DHC-6/77 Horizontal Stabiliser Centre Hinge Bracket Flange (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001 (1) of CASR. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct an unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Viking Air DHC-6 (Twin Otter) Series Aeroplanes

AD/DHC-6/77 Horizontal Stabiliser - Centre
Hinge Bracket Flange 4/2019

Applicability:

All Viking Air (De Havilland Canada) DHC-6 Model aircraft.

Requirement:

1.    Carry out a fluorescent dye penetrant inspection of all flanges of Horizontal Stabiliser Hinge Bracket Part Number (P/N) C6TPM1021 in accordance with the technical instructions of Viking Air (de Havilland Canada) Service Bulletin 6/512 Revision 1 dated 24 April 1992 and as in force at the commencement of this AD.

Note:  Transport Canada AD CF-92-05 refers.

Compliance:

1.    a.     Unless previously accomplished in accordance with AD/DHC-6/70, within 250 hours’ time in service after the commencement date of this AD.

b.    Re-inspect at intervals not to exceed every 1200 hours’ time in service after the inspection referred to in the preceding paragraph a.

The repeat inspections are required regardless of hinge bracket replacement.

Compliance with the requirement of AD/DHC-6/70 constitutes compliance with the requirement of this AD.

This AD commences on 15 February 2019.

Background:

In-service cracking has been reported in the horizontal stabiliser centre hinge bracket flange.

This AD is issued to re-instate the requirement of AD/DHC-6/70 which was inadvertently cancelled due to an administrative error.

Benjamin Wilson
Delegate of the Civil Aviation Safety Authority

7 February 2019