AD/HS 125/168 - Engine Overspeed Control (Cth)

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES

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 CAR 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 125/168 Engine Overspeed Control 3/2003

Applicability: Model Hawker 800XP aeroplanes, as listed in Raytheon Service Bulletin SB 76-3480 dated August 2001.

Requirement: Carry out the following actions in accordance with SB 76-3480:

1. Install a four-inch jumper wire between terminals 1 and 3 on the computer control switch "NF".

2. Install a six-inch jumper wire between terminals 1 and 3 on the computer control switch "NG".

3. Tie and stow the jumper wires on the computer control switches "NF" and "NG" using tie-wrap.

Note: FAA AD 2002-26-22 Amdt 39-13011 refers.

Compliance: Within 3 months or 300 hours time in service after the effective date of this Directive, whichever occurs first.

This Airworthiness Directive becomes effective on 20 March 2003.

Background: This Directive requires the installation of jumper wires on the computer control switches to power the digital electronic engine control when overspeed protection is selected, together with the tying and stowing of the jumper wires on the switches. These actions are intended to prevent loss of the overspeed protection function without the flight crew's awareness, which could result in engine overspeed and possible uncommanded engine shutdown.