AD/Cessna 750/5 Reset Circuit Breakers Replacement (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.

Cessna 750 (Citation X) Series Aeroplanes

AD/CESSNA 750/5 Reset Circuit Breakers - Replacement 1/2010

Applicability:

Model 750 aeroplanes with serial numbers -0001 to -0100 inclusive.

Requirement:

Action in accordance with FAA AD 2002-23-05 Amendment 39-12949.

Note:  Cessna Service Bulletins SB750-24-15, dated 7 May, 1999, and SB750-24-15 Revision 1, dated 24 May, 1999 also refer.

Compliance:

Unless already accomplished, as specified in Requirement document.

This Airworthiness Directive becomes effective on 28 January 2010.

Background:

This AD is prompted by a report to the FAA by the aeroplane manufacturer indicating that the trip levels for the reset circuit breakers installed in the auxiliary hydraulic pump system and the King KHF 950 high frequency system(s) are too high, which can prevent corresponding high current remote control circuit breakers from tripping when excessive loads are present.  The actions specified by this AD are intended to prevent overloading of the affected aeroplane electrical wiring and circuits, which could result in a fire.

Mike Higgins
Delegate of the Civil Aviation Safety Authority

13 January 2010