Service Difficulty Advisory

No. AV-2007-03R1
20 May 2009

FLEXIBLE FUEL MANIFOLDS
PRATT & WHITNEY CANADA
PW100 SERIES ENGINES

The PW100 series flexible fuel manifold was introduced to replace the original, rigid fuel manifold configuration. Although both manifold configurations deliver atomized fuel to the combustion chamber in the same manner, the flex manifold does not use the transfer-tube design and is less labor intensive during removal and installation of the engine fuel nozzles.

Since introduction of the flexible manifold, there have been instances of manifold nuts being improperly torqued during installation, resulting in fuel leaks. More seriously, an engine fire resulted in two of the above events. Although the primary and secondary sealing features at each nozzle provide effective sealing, it is essential that the fuel manifold nut be properly torqued to maintain the integrity of the seal.

To ensure that the correct torque procedures are accomplished; Pratt & Whitney Canada (P&WC) has introduced a tool kit (PWC 56616). This kit includes a pre-set torque wrench that provides for easy installation and removal of components. This information can be found in P&WC Service Information Letter (SIL) PW100-098R2.

In order to prevent further fuel leaks and engine fires, Transport Canada Civil Aviation (TCCA) recommends that maintainers, operators and overhaul agencies comply with the aforementioned SIL PW100-098R2 at the earliest opportunity.

Malfunctions, defects or failures occurring on aeronautical products should be reported to Transport Canada, Continuing Airworthiness, Ottawa, Ontario, via the Service Difficulty Reporting program.

For further information, please contact a Transport Canada Centre, or contact Mr. Barry Caldwell, Continuing Airworthiness, Ottawa, telephone 613-952-4358 or e-mail barry.caldwell@tc.gc.ca

For Director, Aircraft Certification

D. Ferguson
Acting Chief, Continuing Airworthiness

Note: For the electronic version of this document, please consult the following Web address: www.tc.gc.ca/eng/civilaviation/certification/menu.htm

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