AD/CF34/8 Amdt 1 B Sump Screen (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/CF34/8 and issues the following 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.

General Electric Turbine Engines - CF34 Series

AD/CF34/8 Amdt 1 B Sump Screen 4/2005

Applicability:

General Electric Company (GE) CF34-3Al, -3B and -3B1 turbofan engines with scavenge screens part numbers (P/Ns) 4047T95P01 and 5054T86G02 installed in the B-sump oil scavenge system.

Note 1:  These engines are installed on, but not limited to, Bombardier Inc. (Canadair) Model CL-600-2A12, CL-600-2B16 and CL-600-2B19 aeroplanes.

Requirement:

1.    Initial Inspection and Cleaning of B-Sump Screens

Perform an initial visual inspection and cleaning of scavenge screens, P/Ns 4047T95P01 and 5054T86G02, installed in the B-sump oil scavenge system, in accordance with Paragraphs 3A through 3B of the Accomplishment Instructions of General Electric Aircraft Engines (GE) Alert Service Bulletin (ASB) CF34-AL S/B 79-A0014, Revision 3, dated 31 January 2003; or ASB CF34-BJ S/B 79- A00l5, Revision 3, dated 31 January 2003.

2.    Repetitive Inspections and Cleaning

Perform repetitive visual inspections and cleaning of scavenge screens, P/Ns 4047T95P01 and 5054T86G02, installed in the B-sump oil scavenge system, in accordance with Paragraphs 3A through 3B of the Accomplishment instructions of GE ASB CF34-AL S/B 79-A00 14, Revision 3; and ASB CF34-BJ S/B 79-A00l5, Revision 3.

3.    Terminating Actions

Install new screenless fittings or fittings that have been reworked to remove the screens, in the B-sump oil scavenge system, in accordance with GE ASB CF34-AL S/B 79-A00l6, dated 17 June 2002; or ASB CF34-BJ S/B 79-A0017, dated 17 June 2002.

Completion of Requirement 3 of this Directive provides terminating action to this Directive.

Note 2:  FAA AD 2003-05-10R1 Amdt 39-13337 refers.

Compliance:

1.    Initial Inspection and Cleaning Schedule.

Engine hours time-since-new (TSN) or time-since-last-shop-visit (TSLSV)	Inspect and clean
(1)  Fewer than 4,000 hours TSN or fewer than 4,000 hours TSLSV if it can be confirmed that both the B-sump scavenge screens were cleaned and the B-sump and combustor frame (strut tubes) were removed from the engine and cleaned at that prior shop visit.	Before 4,000 hours TSN or TSLSV.
(2)  Fewer than 1,000 hours TSLSV if it can NOT be confirmed that both the B sump scavenge screens were cleaned and the B-sump and combustor frame (strut tubes) were removed from the engine and cleaned at that prior shop visit.	Before 1,000 hours TSLSV.
(3)  4,000 hours or greater TSN or 4,000 hours or greater TSLSV if it can be confirmed that both the B-sump scavenge screens were cleaned and the B sump and combustor frame (strut tubes) were removed from the engine and cleaned at that prior shop visit, or 1,000 hours or greater TSLSV if it can NOT be confirmed that both the B-sump and combustor frame (strut tubes) were removed from the engine and cleaned at that prior shop visit.	Within 500 hours time-in-service (TIS) after the effective date of this Directive.

2.    Repetitive Inspections and Cleaning.

(a)   At intervals not to exceed 200 hours time-since-last-inspection (TSLI), if no coke is found in screens during initial or any prior inspections, or

(b)   At intervals not to exceed 100 hours TSLI, if coke is found in screens during initial or any prior inspections.

3.    Terminating Actions.

Unless previously accomplished:

(a)   For engines with more than 4,000 hours TSN, within 500 hours TIS after the effective date of this AD, or within 1,000 hours TSLSV, whichever occurs first.

(b)   For engines with less than or equal to 4,000 hours TSN, prior to 4,500 hours TSN. This constitutes terminating action to the inspections required in paragraph 2 of this AD.

This Amendment becomes effective on 14 April 2005.

Background:

This Directive was issued requiring the inspection and cleaning of the B-sump oil scavenge screen.  The requirement is in response to five in-flight shut down events resulting from the loss of B-sump oil scavenging.  In two of the events, there was turbine stage separation and in two of the other events, there was separation of the fan drive shaft.

This amendment includes terminating action to the initial and repetitive inspections detailed.

The original issue of this Directive became effective 16 May 2002.

James Coyne
Delegate of the Civil Aviation Safety Authority

3 March 2005