1AD/BAe 146/88 Amdt 2 - Engine Start Electrical Circuit

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AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/BAe 146/88 Amdt 1 and issues the following 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.

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British Aerospace BAe 146 Series Aeroplanes

AD/BAe 146/88

Amdt 2

Engine Start Electrical Circuit 11/2001

Applicability: Avro 146-RJ70 and BAe 146 series aeroplanes detailed in BAe Systems BAe 146 Series/Avro 146-RJ Series Mandatory Modification Service Bulletin SB.80-18- 50293A dated 18 January 2001 or Revision 1 dated 4 July 2001.

BAE 146 Series 100 aeroplanes detailed in BAe Systems BAe 146 Series/Avro 146- RJ Series Mandatory Modification Service Bulletin SB.80-019-50293B dated 6 July 2001.

BAE 146 Series 200 aeroplanes detailed in BAe Systems BAe 146 Series/Avro 146- RJ Series Mandatory Modification Service Bulletin SB.80-020-50293C dated 6 July 2001.

Requirement: Modify the engine electrical start circuit in accordance with either BAe Systems SB.80-18-50293A, SB.80-18-50293A Revision 1, SB.80-019-50293B or SB.80-020- 50293C.

Note: CAA(UK) AD 003-01-2001 refers.

Compliance: Remains unchanged as “Before 20 December 2002”.

This Amendment becomes effective on 1 November 2001.

Background: Current Crew and Maintenance procedures have failed to protect the soft start resistor in the event of component failures, which could result in the resistor overheating and, in some cases, smoke and fumes entering the cabin.

The modification required by this Directive introduces a changeover contactor and protection circuit, which includes a time delay relay. This modification will isolate the start busbar should start power be supplied through the soft start resistor for more than 1.5 seconds. The circuit is also designed so that failure of the changeover contactor to energise will result in a hard start rather than a failed engine start.

Amendment 1 introduced a revised Service Bulletin that provides an alternate method of compliance for modified aeroplanes.