AD/DHC-8/126 Spoiler Cable Disconnect Sensing System (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 (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes
| AD/DHC-8/126 | Spoiler Cable Disconnect Sensing System | 8/2006 |
Applicability: | DHC-8 Models 102, 103, 106, 201, 202, 301, 311, 314 and 315 aircraft, serial numbers (S/N) 003 through 599 inclusive. |
Requirement: | 1. For aircraft S/N 124, 131, 137 and 140 through 561 inclusive - Incorporate Modsum 8Q100898 to install the spoiler cable disconnect sensing device. Bombardier Service Bulletin 8-27-89, Revision E, dated 27 January 2005, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada, provides approved instructions for incorporating Modsum 8Q100898 (See Note 2). |
| 2. For aircraft S/N 003 through 123 inclusive, 125 through 130 inclusive, 132 through 136 inclusive, 138 and 139 - Incorporate Modsums 8Q100898 and 8Q101443 to install the spoiler cable disconnect sensing device and to correct potential spoiler cable interference condition. Bombardier Service Bulletin | |
| 3. For aircraft S/N 003 through 599: | |
| a. Incorporate Modsum 8Q101445 to rework the spoiler cable disconnect sensing circuit. Bombardier Service Bulletin 8-27-103, Revision A, dated 12 February 2004, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada, provides approved instructions for incorporating Modsum 8Q101445 (See Note 4). | |
| b. If Modsum 8Q100898 has not yet been incorporated, incorporate Modsum 8Q101445 in conjunction with Modsum 8Q100898 (refer to Requirements 1 and 2 of this Directive, as applicable) (See Note 4). |
| Note 1: The mandatory operational check requirement for the spoiler cable disconnect system (Modsum 8Q100898) is detailed in Part 2 of Maintenance Program Manual, Airworthiness Limitations (AWL), Task Number 2760/14. It was introduced by Temporary Revisions AWL-88 (Series 100), AWL 2-28 (Series 200) and AWL-3-95 (Series 300), all dated 5 August 2004. Temporary Revision AWL-88 (Task Number 2760/14) has since been incorporated in Revision 17 of Part 2, AWL's, dated 19 April 2005, of the Series 100 Maintenance Program Manual. | |
| Note 2: Installation of Modsum 8Q100898, in accordance with the original issue, Revision A, B, C or D of Bombardier Service Bulletin 8-27-89, prior to the effective date of the Directive, is considered acceptable for compliance with Requirements 1 and 2 for installation of this particular Modsum. | |
| Note 3: Installation of Modsum 8Q101443, in accordance with Revision C or D of Bombardier Service Bulletin 8-27-89, prior to the effective date of the Directive, is considered acceptable for compliance with Requirement 2 for installation of this particular Modsum. | |
| Note 4: Installation of Modsum 8Q101445, in accordance with the original issue of Bombardier Service Bulletin 8-27-103, prior to the effective date of the Directive, is considered acceptable for compliance with Requirement 3 for installation of this particular Modsum. | |
| Note 5: Transport Canada AD CF-2006-13 refers. | |
Compliance: | For Requirements 1, 2 and 3 - Within 24 months after the effective date of this Directive. |
| This Airworthiness Directive becomes effective on 3 August 2006. | |
Background: | Bombardier Aerospace identified that a roll spoiler cable failure could result in an unacceptable amount of roll spoiler deflection, which could result in reduced controllability of the aircraft. To address this condition, Modsum 8Q100898 was issued to introduce a spoiler cable disconnect sensing device. This modification has been installed in production on aircraft serial numbers 562 and subsequent. An associated operational check has also been introduced (See Note 1). In addition, Modsum 8Q101443 was issued to address a potential spoiler cable interference condition on aircraft S/N 003 through 123, 125 through 130, 132 through 136, 138 and 139, which do not yet have a spoiler cable tension regulator (Mod 8/0708) installed. |
| Following incorporation of the spoiler cable disconnect sensing device on several aircraft, it was noted that, in the event of a spoiler cable failure, only the ROLL SPLR INBD HYD caution light will be illuminated until the aircraft speed decreases below 135 kts, at which time the ROLL SPLR OUTBD HYD caution light will also be illuminated. Modsum 8Q101445 has been issued to rework the sensing circuit caution light indication to ensure that it is consistent for spoiler cable disconnects above and below 135 kts. This modification has been installed in production on aircraft serial numbers 600 and subsequent. |
James Coyne
Delegate of the Civil Aviation Safety Authority
22 June 2006
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