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 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 F50 (F27 Mk 50) Series Aeroplanes

AD/F50/88 Power Plant - Feathering Pump 13/2004

TX

Applicability: Fokker Aircraft B.V Model F.27 Mk.050, Mk.0502 and Mk.0604, all serial numbers.

Requirement:  1.  Visually inspect both engines externally in two specific areas for any indication of oil leakage in accordance with the instructions as detailed in Fokker Services All Operator Message AOF50.037 (ref TS04.57535) dated 2 November 2004.

The pilot may carry out requirement 1 of this Directive provided the pilot has completed an approved training program.

Note 1: Fokker Services All Operator Message AOF50.037 includes graphics to show the specific areas that need to be inspected.

2.         If any indication of oil leakage is found during the inspection as detailed in Requirement 1 of this Directive, perform a detailed inspection for oil leakage at the feathering pump of the affected engine in accordance with Part 1 of the Accomplishment Instructions of Fokker Services SB F50-61-023 dated 3 November 2004 or later CAA-NL approved revision.

3.         Perform a detailed inspection for oil leakage at the feathering pump on both engines in accordance with Part 1 of the Accomplishment Instructions of Fokker Services SB F50-61-023 dated 3 November 2004 or later CAA-NL approved revision.

4.        If during the inspection as detailed in Requirement 2 or 3 of this Directive, oil leakage is found at the feathering pump mounting pad, replace the O-rings of the affected feathering pump and mounting pad gasket (if installed) with Part 2 of the of the Accomplishment Instructions of Fokker Services SB F50-61-023 dated 3 November 2004 or later CAA-NL approved revision.

Note 2: Civil Aviation Authority Netherlands BLA nr AD 2004-129 refers.

Compliance: For Requirement 1: Prior to each take-off after the effective date of this Directive.

For Requirement 2: Before further flight.

For Requirement 3: At the intervals specified in the requirement document.

Fokker F50 (F27 Mk 50) Series Aeroplanes

AD/F50/88 (continued)

For Requirement 4: Before further flight.

This Airworthiness Directive becomes effective on 15 November 2004.

Background: This Directive is addition to those requirements detailed in AD/F50/85. That Directive requires replacement of a certain gasket. This action has not been satisfactory in addressing the unsafe condition. There have been several incidents involving in-flight shut down or aborted take-offs due to oil leakage at the feathering pump. It has been determined that such leakage can be readily identified at the intervals specified in this Directive to allow timely rectification of any defects discovered and prevent the unsafe condition from occurring.

James Coyne

Delegate of the Civil Aviation Safety Authority 10 November 2004

The above AD is notified in the Commonwealth of Australia Gazette on 15 November 2004.