AD/CL-600/95 Air-Driven Generator Internal Wiring (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.

Bombardier (Canadair) CL-600 (Challenger) Series Aeroplanes

AD/CL-600/95 Air-Driven Generator - Internal Wiring 4/2008 DM

Applicability:	Model CL-600-2B19 aeroplane with serial numbers (S/N) 7305 through 7990, 8000 and subsequent.
Requirement:	1.    For aeroplanes with S/N 7305 through 7990 and 8000 through 8083 -
a.     Inspect the S/N of the installed air driven generator (ADG).  If the S/N is not listed in paragraph 1.A of Bombardier Aerospace Service Bulletin (SB) 601R-24-113, Revision A, dated 11 August 2005, or later revision approved by the Chief, Continuing Airworthiness, Transport Canada, no further action is necessary.
b.    If as a result of the Requirement 1.a. inspection it is determined that the ADG S/N is listed in the SB inspect the ADG identification plate.  If it is marked with the symbol “24-2” (refer Hamilton Sundstrand SB ERPS10AG-24-2), no further action is necessary.
c.     If the ADG identification plate is not marked with the symbol “24-2” modify the ADG wiring in accordance with the Accomplishment Instructions in SB 601R-24-113, Revision A, or later revision approved by the Chief, Continuing Airworthiness, Transport Canada.
Note 1:  Previous inspection, and modification as required, in accordance with Bombardier Aerospace SB 601R-24-113, original issue, dated 22 April 2004, or Revision A, dated 11 August 2005, is considered satisfactory for compliance with Requirement 1 of this directive if the ADG has not been replaced since SB incorporation.
Note 2:  It is permissible to satisfy Requirement 1 by a review of the aircraft maintenance records.
2     For aeroplanes with S/N 7305 through 7990, 8000 and subsequent - ADGs with part number 604-90800-1 (761339C), 604-90800-17 (761339D) or 604-90800-19 (761339E) and with a S/N listed in Table 1 may not be installed on any aeroplane as a replacement spare, unless it is identified with the symbol “24-2” (refer Hamilton Sundstrand SB ERPS10AG-24-2) on the identification plate.

Table 1 - List of Affected S/N (S/N are inclusive)
0101 to 0132 0134 to 0167 0169 to 0358	0360 to 0438 0440 to 0456 0458 to 0467	0469 0471 to 0590 0592 to 0597	0599 to 0745 0747 to 1005 1400 to 1439
Note 3:  Transport Canada AD CF-2008-09 refers.
Compliance:	For Requirement 1 - Within 12 months after the effective date of this Directive.
For Requirement 2 - As of the effective date of this Directive.
This Airworthiness Directive becomes effective on 21 February 2008.
Background:	Following in-flight test deployments, several ADGs failed to come on-line.  Investigation revealed that, as a result of a wiring anomaly that had not been detected during ADG manufacture, a short circuit was possible between certain internal wires and their metallic over-braided shields, which could result in the ADG not providing power when deployed.  This Directive mandates checking of the ADG and modification of the ADG internal wiring, if required.  It also prohibits future installation of unmodified ADGs.

David Punshon
Delegate of the Civil Aviation Safety Authority

13 February 2008