AD/HS 125/183 Cockpit Ventilation and Avionics Cooling System Blower Motor (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 125/183 Cockpit Ventilation and Avionics
Cooling System Blower Motor 6/2009

Applicability:	Hawker Beechcraft Corporation Model BH.125 series 600A aeroplanes and Model HS.125 series 700A aeroplanes, as identified in Hawker Beechcraft Mandatory Service Bulletin SB 24-3850, dated January 2008, which have been modified in accordance with United States Federal Aviation Administration (FAA) Supplemental Type Certificate SA2271SW.
Requirement:	1.    Inspect the wiring diagrams pertaining to the cockpit blowers and compare with the current aeroplane configuration, in accordance with the Accomplishment Instructions of SB 24-3850.
2.    If the current aeroplane configuration does not match the applicable cockpit blower wiring diagrams, rework the wiring using a method approved by the Manager, Special Certification Office, ASW-190, Rotorcraft Directorate, FAA.  For the determination to be approved by the Manager, Special Certification Office, as required by this paragraph, the Manager's approval letter must specifically refer to FAA AD 2009-08-04.
3.    If the current aeroplane configuration matches the applicable cockpit blower wiring diagrams, rework the wiring in accordance with the Accomplishment Instructions of SB 24-3850.
Later revisions of the above SB, approved by the FAA as an Alternate Method of Compliance (AMOC) to FAA AD 2009-08-04, are considered acceptable for compliance with the equivalent Requirements of this Directive.
Note:  FAA AD 2009-08-04 Amdt 39-15877 refers.
Compliance:	For Requirement 1 - Within 600 hours time in service or six months after the effective date of this Directive, whichever occurs first.
For Requirements 2 and 3 - Before further flight after the Requirement 1 inspection.
This Airworthiness Directive becomes effective on 4 June 2009.

Background:

The FAA has received a report indicating that a cockpit ventilation and avionics cooling system blower motor seized and gave off smoke.

This Directive requires inspecting the wiring diagrams pertaining to the cockpit blowers and comparing with the current airplane configuration, together with any necessary reworking of the wiring.  The Directive is issued to prevent smoke and fumes in the cockpit in the event that a blower motor seizes and overheats due to excessive current draw.

James Coyne
Delegate of the Civil Aviation Safety Authority

24 April 2009