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 1998. 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.
GippsAero GA8 Series Aeroplanes
Engine Mount Fire Seal Washer
All GA8-TC 320 aircraft.
Comply with GippsAero Service Bulletin SB-GA8-2014-115 Issue 1, or later approved revision.
Within 300 hours flight time or 12 months, from the effective date of this AD, whichever occurs first.
The effective date of this AD is 1 December 2014.
A recent review of the engine mount installation on the GA8-TC 320 aircraft has highlighted the omission of engine mount fire seal washers during the assembly process.
The current engine mount configuration does not meet the certification basis for the aircraft, specifically regulation 23.865 of the Federal Aviation Regulations of the United States of America, where engine mounts located in designated fire zones are required to be suitably shielded so that they are capable of withstanding the effects of a fire.
The Gippsland Aeronautics GA8-TC 320 aircraft require the installation of an approved steel washer at each of the engine mount locations to address a potential risk of reduced engine retention capability in the event of a fire.
Delegate of the Civil Aviation Safety Authority
24 November 2014