Ad/DHC-8/142 - Spoiler Disconnect Sensing Device (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-8/142 Spoiler Disconnect Sensing Device 10/2008

Applicability:

Bombardier Inc. DHC-8 Models 102, 103, 106, 201, 202, 301, 311, 314 and 315, Serial Numbers 003 thru 644 inclusive; and

Bombardier Inc. DHC-8 Models 400, 401 & 402, Serial Numbers 4003, 4004, 4006 and 4008 thru 4164 inclusive.

Requirement:

1.    Applicable to Bombardier Inc. DHC-8 Models 102, 103, 106, 201, 202, 301, 311, 314 and 315, Serial Numbers 003 thru 561:

(a)   For aircraft that have already had the fuselage spoiler cable disconnect sensing device, Modsum 8Q100898, installed - Inspect the fuselage spoiler cable disconnect sensing device for correct assembly in accordance with Paragraph 3.B, PART A of Bombardier Service Bulletin (SB) 8-27-107, initial issue dated 16 October 2007, or later approved revisions.

Note 1:  Modsum 8Q100898 may have already been incorporated in service (Service Bulletin 8-27-89 and AD/DHC-8/126 apply).

(b)   For aircraft that have not yet had the fuselage spoiler cable disconnect sensing device, Modsums 8Q100898, installed - Concurrently with the incorporation of Modsums 8Q100898 (SB 8-27-89 and AD/DHC-8/126 apply), inspect the fuselage spoiler cable disconnect sensing device for correct assembly in accordance with Paragraph 3.B, PART A of Bombardier SB 8-27-107, initial issue dated 16 October 2007, or later approved revisions.

(c)   If the sensing device is correctly assembled, no further action is required.

(d)   If an incorrectly assembled sensing device is detected, inspect the components, replace if worn or damaged and correctly re-assemble the device in accordance with Paragraph 3.B, PART B of Bombardier SB
8-27-107, initial issue dated 16 October 2007, or later approved revisions.

2.    Applicable to Bombardier Inc. DHC-8 Models 102, 103, 106, 201, 202, 301, 311, 314 and 315, Serial Numbers 562 thru 644:

Note 2:  The fuselage spoiler cable disconnect sensing device was installed in production.

(a)   Inspect the fuselage spoiler cable disconnect sensing device for correct assembly in accordance with Paragraph 3.B, PART A of Bombardier SB
8-27-107, initial issue dated 16 October 2007, or later approved revisions.

(b)   If the sensing device is correctly assembled, no further action is required.

(c)   If an incorrectly assembled sensing device is detected, inspect the components, replace if worn or damaged and correctly re-assemble the device in accordance with Paragraph 3.B, PART B of Bombardier SB
8-27-107, initial issue dated 16 October 2007, or later approved revisions.

3.    Applicable to Bombardier Inc. DHC-8 Models 400, 401 & 402, Serial Numbers 4003, 4004, 4006 and 4008 thru 4164:

Note 3:  The fuselage spoiler cable disconnect sensing device was installed in production.

(a)   Inspect the fuselage spoiler cable disconnect sensing device for correct assembly in accordance with Paragraph 3.B, PART A of Bombardier SB
84-27-34, initial issue dated 3 October 2007, or later approved revisions.

(b)   If the sensing device is correctly assembled, no further action is required.

(c)   If an incorrectly assembled sensing device is detected, inspect the components, replace if worn or damaged and correctly re-assemble the device in accordance with Paragraph 3.B, PART B of Bombardier SB
84-27-34, initial issue dated 3 October 2007, or later approved revisions.

Note 4:  Transport Canada AD CF-2008-28 dated 10 July 2008 refers.

Compliance:

Within 1000 flight hours after the effective date of this AD.

This Airworthiness Directive becomes effective on 25 September 2008.

Background:

A fuselage spoiler cable disconnect sensing device was installed in production on later DHC-8 Series 100/200/300 aircraft and on all DHC-8 Series 400 aircraft.  On earlier DHC-8 Series 100/200/300 aircraft, its installation was mandated by AD/DHC-8/126.

However, several incorrectly assembled spoiler cable disconnect sensing devices have recently been discovered on in-service aircraft.  A pulley and plastic spacer had been inadvertently interchanged during assembly of the device in production, resulting in the spoiler cable sliding on the spacer rather than running on the pulley, as designed.

Continued operation with an incorrectly assembled spoiler cable disconnect sensing device could result in impaired operation of the sensing device and/or an eventual fuselage spoiler cable disconnect, with possible reduced controllability of the aircraft.

James Coyne
Delegate of the Civil Aviation Safety Authority

6 August 2008