AD/G1159/51 APU Firewall (Cth)

AIRWORTHINESS DIRECTIVE

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 the 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.

Gulfstream (Grumman) G1159 and G-IV Series Aeroplanes

AD/G1159/51 APU Firewall 10/2009 DM

Applicability:

Model G-IV series aircraft, serial numbers 1000 and subsequent.

Model GIV-X series aircraft, serial numbers 4001 through 4146, and 4148 through 4150.

Model GV aircraft, serial numbers 501 and subsequent.

Model GV-SP series aircraft, serial numbers 5001 through 5204, 5206 through 5217 and 5219.

Requirement:

Action in accordance with the technical requirements of FAA AD 2009-17-01 Amdt 39-15991.

Compliance:

As specified in the Requirement document.

This Airworthiness Directive becomes effective on 26 August 2009.

Background:

The FAA received notification from the aircraft manufacturer that an improper, flammable sealant was used on the interior and exterior of the APU enclosure (firewall).  The actions required by this Directive are intended to prevent this flammable sealant from igniting the exterior surfaces of the APU enclosure under certain anomalous conditions such as APU failure/APU compartment fire, which could result in propagation of an uncontained fire to other critical areas of the aircraft.

David Villiers
Delegate of the Civil Aviation Safety Authority

14 August 2009