AIRWORTHINESS DIRECTIVE On the commencement date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below repeals Airworthiness Directive (AD) AD/GA8/7 and issues the following AD under subregulation 39.001 (1) of CASR 1998 and subsection 33 (3) of the Acts Interpretation Act 1901. 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 AD/GA8/7 Amdt 1 Fuel System Ventilation and Drainage Modification 23/2017 Applicability: GippsAero GA8 and GA8-TC 320 aircraft as identified in GippsAero Service Bulletin SB-GA8-2012-96 Issue 6, as in force at the time of commencement of this AD. Requirement: 1 Modify the aircraft in accordance with Part 1 of GippsAero Service Bulletin SB-GA8-2012-96 Issue 6 as in force at the time of commencement of this AD; and 2 If a cargo pod part number GA8-255004-017 or GA8-255004-019 is installed in the aircraft - modify the cargo pod in accordance with Part 2 of GippsAero Service Bulletin SB-GA8-2012-96 Issue 6 as in force at the time of commencement of this AD; and 3 Modify the aircraft in accordance with Part 3 of GippsAero Service Bulletin SB‑GA8-2012-96 Issue 6 as in force at the time of commencement of this AD. Note: Compliance with requirements (1) and (2) of the original issue of AD/GA8/7 constitutes compliance with the equivalent requirements of this directive, AD/GA8/7 Amdt 1. Compliance: For requirement 1: compliance before 100 flight hours from 6 September 2013, (the effective date of the original issue of AD/GA8/7) or if the aircraft has already flown 100 flight hours before further flight. For requirement 2: compliance concurrently with requirement 1. For requirement 3: compliance before the earlier of the following: (a) 100 flight hours; or (b) 3 months after the effective date of this AD. This AD commences on 20 November 2017. Background: The GippsAero GA8 and GA8-TC 320 aircraft Mk II fuel system features an integral sump tank located in the floor structure forward of the co-pilot seat. The current configuration of the compartments adjacent to the Mk II sump tank does not meet the requirements of regulation 23.967 (b) of the Federal Aviation Regulations of the United States of America in that they are not suitably ventilated and drained to prevent the accumulation of flammable fluids or vapours. Amendment 1 of this directive mandates ventilation of the area around the integral sump tank as presented in SB-GA8-2012-96 Issue 6 to meet the requirements of regulation 23.967 (b) of the Federal Aviation Regulations of the United States of America. Christopher De Luis Delegate of the Civil Aviation Safety Authority 13 November 2017