AD/HS 125/180 DA-A Panel Bus Bars (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.

British Aerospace BAe 125 Series Aeroplanes

AD/HS 125/180 DA-A Panel Bus Bars 8/2006

Applicability:	Raytheon Model Hawker 800XP aeroplanes, serial numbers 258541, 258556, 258567 through 258609 inclusive, 258611 through 258628 inclusive, 258630 through 258684 inclusive, and 258686 through 258728 inclusive.
Requirement:	1.    Perform a detailed inspection of the four bus bars in the DA-A panel to ensure that the bus bars match the panel configuration and clearance is adequate between the bus bars and adjacent components, in accordance with the Accomplishment Instructions of Raytheon Service Bulletin SB 24-3745, Revision 1, dated September 2005.
2.    Carry out any applicable corrective actions of any discrepancies found during the Requirement 1 inspection in accordance with SB 24-3745 Revision 1.
Note 1:  For the purposes of this AD, a detailed inspection is: "An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity.  Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate.  Inspection aids such as mirror, magnifying lenses, etc., may be necessary.  Surface cleaning and elaborate procedures may be required.''
Inspections accomplished before the effective date of this Directive in accordance with Raytheon SB 24-3745, dated September 2005, are considered acceptable for compliance with the inspections specified in Requirement 1.
Later revisions of the SB 24-3745, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2006-11-07, are considered acceptable for compliance with the equivalent Requirements of this Directive.
Note 2:  FAA AD 2006-11-07 Amdt 39-14611 refers.
Compliance:	For Requirement 1 - Within 30 days after the effective date of this Directive.
For Requirement 2 - Before further flight after the Requirement 1 inspection.
This Airworthiness Directive becomes effective on 3 August 2006.

Background: The FAA has received two reports of inadequate clearance between the bus bars in the DA-A panel.  This Directive is issued to prevent insufficient electrical isolation for the electrical bus configuration and inability of the flight crew to isolate the bus bars in an emergency situation involving a dual generator failure, which could result in extra loads on the main ship batteries and consequent loss of power to the main essential bus.

James Coyne
Delegate of the Civil Aviation Safety Authority

22 June 2006