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 39.1 (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.

Learjet 60 Series Aeroplanes

AD/LJ60/2 Fuel Crossflow Tube 4/2004

Applicability: Learjet Model 60 aeroplanes serial numbers (S/N) 60-001 through 60-145 inclusive.

Requirement: 1. Inspect the fuel crossflow tube or review aeroplane records to determine whether part number (P/ N) 6026020-005 is installed.

2.         If P/N 6026020-005 is found installed during the review or inspection required by Requirement 1 of this Directive measure the clearance between the fuel crossflow tube and the flight control cables to determine if it is at least 0.35 inch, per paragraph 2.B.(8) of the Accomplishment Instructions of Bombardier Alert Service Bulletin A60-28-3, Revision 2, dated 26 October 1998.

3.         If P/N 6026020-005 is not found installed during the review or inspection required by Requirement 1 of this Directive, replace the existing fuel crossflow tube with a new fuel crossflow tube having P/N 6026020-005, and measure the clearance between the newly installed fuel crossflow tube and the flight control cables in accordance with paragraph 2.A. of the Accomplishment Instructions of:

Bombardier Service Bulletin 60-28-4, Revision 2, dated 22 August, 2001 for aeroplanes having serial numbers 60-001 through 60-055, and

Bombardier Service Bulletin A60-28-3, Revision 2 for aeroplanes having serial numbers 60-056 through 60-145.

4.         If the clearance is 0.35 inch or more, as determined in Requirement 2 or 3 of this Directive, no further action is required.

5.         If the clearance is less than 0.35 inch, as determined in Requirement 2 or 3 of this Directive, repair per an approved method.

6.         Only install fuel crossflow tubes having P/N 6026020-005.

Note: FAA AD 2003-19-11 Amdt 39-13314 refers.

Learjet 60 Series Aeroplanes

AD/LJ60/2 (continued)

Compliance: For Requirement 1: Within 25 flight hours after the effective date of this Directive.

For Requirement 2, 3: Within 90 days after the completion of requirement 1 of this Directive.

For Requirement 5: Before further flight.

For Requirement 6: From the effective date of this Directive.

This Airworthiness Directive becomes effective on 15 April 2004.

Background: This Directive requires replacement of certain fuel crossflow tubes, and the inspection of all fuel crossflow tubes for adequate clearance to surrounding flight control cables. This will prevent chafing of the fuel crossflow tube that could result in loss of fuel from both main fuel tanks during cross-feeding operations.

James Coyne

Delegate of the Civil Aviation Safety Authority 4 March 2004

The above AD is notified in the Commonwealth of Australia Gazette on 24 March 2004.