AD/CL-600/105 Engine Throttle Control Gearbox (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-600/105 Engine Throttle Control Gearbox 1/2009

Applicability:

Bombardier CL-600-2A12 (CL601) and CL-600-2B16 (601-3A, 601-3R & CL604) Aircraft.

Requirement:

Revise the Transport Canada approved Maintenance Schedule as per the following:

a)    Incorporate Task 76-10-00-101 in Section 5-10-30 of PSP 601-5 TLMC, as introduced by TR 5-236 for CL601 variant.

b)    Incorporate Task 76-10-00-101 in Section 5-10-30 of PSP 601A-5 TLMC, as introduced by TR 5-236 for CL601-3A & 3R variants.

c)    Incorporate Task 76-11-00-101 in Section 5-10-40 of CL604 TLMC, as introduced by TR 5-2-40 for CL604 variant.

Previous compliance with superseded TLMC TR 5-224 for variant CL 601, and
TR 5-2-31 for variant CL604, satisfies the intention of this AD.

Note:  Transport Canada AD CF-2008-32R2 dated 17 November 2008 refers.

Compliance:

Within 30 days after the effective date of this AD.

Initial compliance with the above-mentioned new TLMC tasks should be carried out in accordance with the Phase-in schedule as detailed in the applicable TRs 5-236 and TR 5-2-40.

This Airworthiness Directive becomes effective on 15 January 2009.

Background:

There have been various reported incidents of throttle jam and engine shutdowns, caused by premature wear of the rack and pinion mechanism of part number (P/N) 2100140-005 and -007 Engine Throttle Control Gearbox (ETCG), installed on Bombardier CL-601 and 604 aircraft.

Bombardier issued service bulletins (SB) 601-0583 (CL601/601-3A,-3R) and
604-76-004 (CL 604), introducing periodic inspection of the affected ETCG rack and pinion mechanisms for wear.

Subject inspection requirement tasks have now been incorporated into the applicable CL601 and CL604 Time Limits Maintenance Checks (TLMCs), through Temporary Revisions (TR), TR 5-236 (for CL601), TR 5-236 (for CL601-3A & -3R) and
TR 5-2-40 (for CL604).

James Coyne
Delegate of the Civil Aviation Safety Authority

27 November 2008