As described in Mustang M-O, in October 2009 P&WC issued a Service Alert Category 3 SB A63069 for premature poppet wear. This is a small metal tube that lets the fuel flow either through the fuel filter or bypasses the fuel filter. Normally when the fuel filter bypass is engaged a CAS message appears. When these poppets were wearing prematurely, the fuel was bypassing the fuel filter without any CAS message.

As of October, there have been no reports of poppet wear in the field. When I spoke to the Orlando (MCO) Tech, he said he had inspected 10 planes (20 engines) and not found any premature wear yet.

The initial Service Bulletin A63069 required a specific inspection interval. If poppet wear was discovered, the old poppet was simply replaced by a new poppet of the same. The new poppet could be equally prone to early wear.

As of December 9, 2009, P&WC released a new Service Bulletin A63071 which supercedes the old SB. The old SB must not be applied from this point on.  Service Centers are no longer authorized to put in the old replacement poppet - they must use the new parts.

The SB must be applied within a specific interval:

"For engines Pre P&WC Service Bulletin No. A63069 with more than 100 hours TTSN:

CATEGORY 3 - P&WC recommends to do this service bulletin within 25 flight hours

upon receipt of this bulletin.

For engines Pre P&WC Service Bulletin No. A63069 with less than 100 hours

TTSN: CATEGORY 3 - P&WC recommends to do this service bulletin no later than 125 flight

hours TTSN.

For engines Post P&WC Service Bulletin No. A63069 and with less than 75 flight hours since SB incorporation:

CATEGORY 3 - P&WC recommends to do this service bulletin within 75 flight hours of SB A63069 incorporation."

See the SB for the precise details.

The new parts do not require any further inspections, so P&WC is confident that the issue is finally resolved. Maintenance costs are covered by P&WC.