AD/F100/30 Amdt 1 Flight Warning Computer Replacement (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/F100/30 and issues the following 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.

Fokker F100 (F28 Mk 0070) Series Aeroplanes

AD/F100/30 Amdt 1 Flight Warning Computer Replacement 17/2011

Applicability:

All F28 Mk 0070 aeroplanes.

Requirement:

Replace the Flight Warning Computer (FWC) with a modified unit, part number
80-0610-3-45, in accordance with Fokker Service Bulletin (SB) F100-31-051 dated 15 August 1998.

Modify the wiring in accordance with Fokker SB F100-31-047 Revision 1 dated
21 March 1997.

Note:  Netherlands AD 1998-110 and EASA AD 2008-0090 refer.

Compliance:

1.    Prior to 22 October 2001.

2.    Either concurrently with, or prior to Requirement 1.

This amendment becomes effective on 25 August 2011.

Background:

In-service experience with Fokker 70 aircraft has shown that full transition to another flight phase could take up to eight seconds from the moment that all relevant input conditions are met.  This may lead to alerts being generated during phases of flight where they should be suppressed.  This directive introduces a new FWC that reduces the time delay between phases of flight to the lowest minimum attainable.

The new computer also changes the flight phase inhibition definition of the REVERSER ENG 1(2) alerts so that these alerts are no longer inhibited during initial climb between 400 and 1000 ft radio altitude.

Amendment 1 is issued to remove F28 Mk 100 aeroplane from the applicability as the AD requirement for this aeroplane type has been superseded by CASA AD/F100/89 (EASA AD 2008-0090) which requires FWC P/N 80-0610-3-45 to be replaced with P/N 80-0610-3-55 on all F28 Mk 100 aeroplanes.

There is no change to the initial requirement of the AD.  The initial issue of this Airworthiness Directive became effective on 22 April 1999.

Mike Higgins
Delegate of the Civil Aviation Safety Authority

23 August 2011