Pratt & Whitney released Service Bulletin A63069 on Oct 14, 2009, about the fuel oil heat exchanger (FOHE) fuel-filter bypass valve and then revised it on Oct 28, 2009. It recommends a visual inspection of the fuel filter bypass valve be performed in the next 25 hrs for engines with more than 200 hrs TTSN and before 225 hrs TTSN for engines currently under 200 hrs TTSN. If this inspection shows both bypass valves (one in each engine on the same aircraft) out of position per the photos in the SB, P&W recommends one fuel metering unit be removed and returned within 25 flight hrs. Regardless of the results of your visual inspection, the SB goes on to recommend the replacement of the bypass valve poppets, springs and the valve bodies with the ones supplied in the parts kit, even if they appear to be in good condition.
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