Service Bulletin 28-4059, Rev. 1: Fuel – Introduction of Improved Fuel Cell Gasket
Issued: August 2011, Revised: September 2015
Synopsis of Change: This Service Bulletin has been revised to introduce fuel cell gasket P/N 50-921587-0011 as a replacement for fuel cell gasket P/N 50-921587-7. Fuel cell gasket P/N 50-921587-9, which was introduced in the original issue of this Service Bulletin, is still allowed. Both replacement gaskets provide improved moisture resistance over the original P/N 50-921587-7 gasket and may be used interchangeably on the same airframe.
If Service Bulletin 28-4059 (issued August, 2011), has been accomplished, it is not necessary to replace the P/N 50-921587-9 gasket with the P/N 50-921587-0011 gasket. The P/N 50-921587-9 gasket may be used until the supply is exhausted. For optimal moisture resistance, it is recommended that the P/N 50-921587-0011 gasket be installed when the fuel cell is opened for maintenance.
Effectivity:
Airplanes Model C90A, (C90B), C90GT, C90GTi, (C90GTx), King Air Serial Numbers LJ-1599 through LJ-2003; Model B200, Super King Air Serial numbers BB-1735 through BB-2016; Model B200C, Super King Air Serial Numbers BL-141 through BL-165; Model B200GT, Super King Air Serial Numbers BY-1 through BY-113; Model B300, (350), (350i), (350ER), Super King Air Serial Numbers FL-284 through FL-741; Model B300C, (350C), (350CER), Super King Air Serial Numbers FM-11 through FM-46.
Spares The following models and serials that have installed gasket P/N 50-921587-7 as a spare part:
All King Air Models: All Serial Numbers.
If you are no longer in possession of the airplane, please forward this information to the present owner.
Reason: This Service Bulletin is being issued to install a more moisture-resistant gasket for use on the fuel cell covers.
Description: This Service Bulletin announces the availability of fluorosilicone rubber gasket, P/N 50-921587-0011, as the preferred replacement for gasket P/N 50-921587-7 and gasket P/N 50-921587-9.
Warranty: Warranty coverage offered in this Service Bulletin will expire six (6) months from the original issue date. After this date, the owner/operator assumes the responsibility for compliance cost. Beechcraft Corporation (BC) reserves the right to void continued warranty coverage in the area affected by this Service Bulletin until the date the Service Bulletin is accomplished by an HBC Authorized Service Center (ASC).
From King Air Model Communiqué 2015-06:
Issued: September 2015
ATA 73 – Fuel Control Unit Inspection
90 Series
Pratt and Whitney Canada recently released P&WC Service Bulletin (SB) No. A1774 recommending that owner/operators inspect their fuel controls.
The Service Bulletin addresses fuel control units (FCU) that are new or newly overhauled and have less than 100 hours time in service. The document recommends inspection of fuel controls for fuel leaks in the metering valve maximum stop area. If fuel leaks are found, replacement of the FCU is required.
The SB is applicable to PT6A-135A, PT6A-21, PT6A-28 and various other model engines. Only FCU serial numbers identified in the PWC service bulletin are affected.
The above information is abbreviated for space purposes. For the entire communication,
go to www.beechcraft.com.
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