AD/DHC-8/34 Amdt 2 Black Thermal Insulation (Cth)

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/DHC-8/34 Amdt 1 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.

Bombardier DHC-8 Series Aeroplanes

AD/DHC-8/34 Amdt 2 Black Thermal Insulation 21/2017

Applicability:	Bombardier DHC-8 aircraft, with models and serial numbers as listed in the Requirement Table.
Requirement:	Remove all black film thermal insulation blankets from the aircraft fuselage and flight compartment and replace them with AN4C Aluminized (silver) film insulation blankets; in accordance with the Part III Accomplishment Instructions of the Bombardier Inc., de Havilland Dash 8 Service Bulletins listed in the following table:
	DHC-8 Models	Serial Numbers	Service Bulletin Numbers
	102, 103, & 106	003 to 353	8-25-89 as in force from time to time
	102, 103, & 106	003 to 371	8-25-90 as in force from time to time
	102, 103, 106, 301, 311, & 314	003 to 337, 339, 341 to 347, 349, 350, 351, 353, & 356	8-25-91 as in force from time to time
	301, 311, & 314	100 to 336, 342, 350, & 356	8-25-92 as in force from time to time
	301, 311, & 314	100 to 336, 342, 350, 356, 365, & 370	8-25-93 as in force from time to time
	Note 1:  Transport Canada AD CF-94-08R1 refers. Note 2:  This Directive is not applicable to aircraft that have had all three de Havilland Modifications 8/2004, 8/2006, and 8/2007 incorporated during manufacture. Note 3:  The words “as in force from time to time” require compliance with the most recent version of the referenced document.
Compliance:	Unless already accomplished in accordance with the previous issue of this Directive, prior to 26 November 2017 or as indicated in Part 1.D of the service bulletins listed in the Requirement Table, whichever occurs later. Note 4:  Previous compliance with the requirement in AD/DHC-8/34 Amdt 1 constitutes compliance with the requirement in this AD.
This AD commences on 26 October 2017.
Background:	Operators have reported corrosion forming on areas of the aircraft where black film thermal insulation blankets are being used. De Havilland’s investigation found that the black film, which covers these insulation blankets, contains carbon. If condensation is present, corrosion may occur in places where the black film is in contact with any aluminium structure. Amendment 1 of this AD was issued in response to a revision of the Transport Canada AD which changed the applicability to align with the applicability of the latest revision of the mandated service bulletins. Amendment 2 of this AD is issued to correct two minor typographical errors in the serial number range of the last row of the Requirement Table.

Pieter van Dijk
Delegate of the Civil Aviation Safety Authority

16 October 2017