Document ID: chunk:federal_register_of_legislation:F2007L04222:body:0:p2
Version: federal_register_of_legislation:F2007L04222
Segment Type: other
Provision Reference: 
Character Range: 2715–5484

bobbin P/N 638005614 with bobbin P/N 638005637 and install a gasket on the feathering pump of that engine in accordance with the Accomplishment Instructions of Fokker Services SB F50-61-025 or later NAA approved revision.

                6. The replacement of a modified engine with an unmodified (i.e. pre-SB
                F50-61-024 or pre-SB F50-61-025) engine is no longer authorised.

                7. Do not install a replacement engine or QEC unit on any aircraft unless it has been modified in accordance with the Accomplishment Instructions of Fokker Services SB F50-61-025 or later NAA approved revisions.

             After accomplishment of the modification in accordance with Fokker Services SB F50-61-025 on both engines of the aircraft the repetitive visual and detailed inspections in Requirements 1, 2 and 3 of this AD may be discontinued.

             Note 2:  EASA AD 2007-0203 dated 1 August 2007 refers.  This AD supersedes CAA Netherlands AD (BLA) 2003-089/2 and BLA 2004-129.
Compliance:     1. Prior to each take-off after the effective date of this AD.

                2. Before further flight.

                3. At the intervals specified in the requirement document.

                4. Before further flight.

                5. At the next scheduled or unscheduled aircraft maintenance opportunity with sufficient aircraft downtime but no later than 15 August 2009.

                6. After accomplishment of the modification in accordance with Fokker Services SB F50-61-025.

                7. From the 15 August 2009.
             This Amendment becomes effective on 26 October 2007.
Background:  This AD was originally in addition to those requirements previously detailed in AD/F50/85.  That AD required replacement of certain parts.  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 AD to allow timely rectification of any defects discovered and prevent the unsafe condition from occurring.

             This amendment supersedes the requirements of AD/F50/85 Amdt 1.  This AD now requires in addition to the existing inspections, the fitment of an improved version of the gasket and bobbin, which interface the feathering pump to the engine.  Once fitted to both engines the inspections currently required by this AD may be discontinued.

   The original issue of this AD became effective 15 November 2004.  AD/F50/85 will be cancelled when this AD becomes effective.

David Punshon
Delegate of the Civil Aviation Safety Authority

23 October 2007