AD/F100/21 Amdt 1 Reverse Thrust Control Maximum Detent (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/F100/21 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 100) Series Aeroplanes

AD/F100/21 Amdt 1 Reverse Thrust Control Maximum Detent 7/2008

Applicability:

Fokker Aircraft B.V.  F28 Mark 0100 aircraft serial numbers 11244 through 11256, 11259 through 11261, 11263, 11268 through 11275, 11277 and 11279 inclusive, fitted with Rolls-Royce (Deutschland) TAY620-15 engines.

This AD is not applicable to aircraft modified in accordance with Fokker Service Bulletin (SB) SBF100-76-016 at any revision status.

Requirement:

1.    Aircraft incorporating Fokker SB SBF100-76-008:

a.     Inspect for adequate clearance between the second detent and surrounding moving parts in accordance with Part 1 of the Accomplishment Instructions of Fokker SBF100-76-010 original issue dated 31 Oct 1993 or Revision 1 dated 12 Dec 2007 or later NAA approved revisions; and

b.    If interference is found during the inspection, install a new second detent in accordance with Part 2 of the Accomplishment Instructions of Fokker SBF100-76-010; or

c.     If inadequate clearance but no interference is found during the inspection, install a new second detent in accordance with Part 2 of the Accomplishment Instructions of Fokker SBF100-76-010; or

d.    If adequate clearance is found during the inspection, install a new second detent in accordance with Part 2 of the Accomplishment Instructions of Fokker SBF100-76-010.

2.    Aircraft NOT incorporating Fokker SB SBF100-76-008:

Install a new second detent in accordance with Part 2 of the Accomplishment Instructions of Fokker SBF100-76-010 original issue dated 31 Oct 1993 or Revision 1 dated 12 Dec 2007 or later NAA approved revisions.

Note:  EASA Airworthiness Directive (AD) No. 2008-0088 dated 13 May 2008 refers.  AD 2008-0088 supersedes CAA Netherlands (CAA-NL) AD (BLA) 93-151 dated
1 Nov 1993.

Compliance:

Requirement 1(a): Remains unchanged as detailed in the original issue of this AD as: within 1,500 flight cycles (FC) after 22 April 1999, unless accomplished earlier.

Requirement 1(b): Before further flight.

Requirement 1(c): Within 250 flight cycles (FC) after the inspection.

Requirement 1(d): Within 3,000 FC after the inspection.

Requirement 2: Remains unchanged as detailed in the original issue of this AD as: within 500 FC after 22 April 1999.

This Amendment becomes effective on 3 July 2008.

Background:

The override force for the normal maximum (second) detent for the reverse thrust control has been found to be too low, which could result in accidental selection of a too high reverse thrust level, affecting the structural life of the horizontal stabilizer attachment.  CASA AD/F100/21 was issued in 1999 requiring replacement of the second detent in accordance with Fokker SBF100-76-010.

Recently, based on operational experience, EASA has issued AD 2008-0089 requiring the removal of the second detent on all TAY650-equipped F28 Mark 0100 aircraft.  The manufacturer (Fokker Services) prompted by EASA AD, has issued Revision1 of Fokker SBF100-76-010, deleting the TAY650-equipped F28 Mark 0100 aircraft serial numbers.

Since a separate CASA AD will be issued reflecting requirements of EASA AD 2008-0089, the current amendment retains the requirements of now superseded
CAA-NL BLA 93-151, and limits the applicability to those aircraft equipped with TAY620-15 engines.

The original issue of this AD became effective on 22 April 1999.

James Coyne
Delegate of the Civil Aviation Safety Authority

22 May 2008