SAIB NM-02-04 —

1 SPECIAL AIRWORTHINESS INFORMATION BULLETIN Aircraft Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration No. NM-02-04 November 1, 2001 We post SAIBs on the internet at "av-info.faa.gov" This is information only. Recommendations are not mandatory. Introduction This Special Airworthiness Information Bulletin (SAIB) alerts you, an owner or operator of Dassault Falcon Jets, that have a single point pressure fueling system installed in accordance with STC SA1851WE, of the potential for refueling vent valve failure due to the installation of incompatible o-rings. This, when accompanied with certain other failures, could result in the inability to transfer and use wing tank fuel. This SAIB also alerts Repair Stations, Mechanics holding Inspection Authorization (IA), and Principal Maintenance Inspectors. This SAIB applies to Aircraft Tank Services single point refueling system installed per STC SA1851WE on Dassault Fan Jet Falcon Fan Jet Falcon Series C Fan Jet Falcon Series D Fan Jet Falcon Series E Mystere Falcon 20-C5 Mystere Falcon 20-D5 Mystere Falcon 20-E5 Note: Rogerson ATS is the current holder of STC SA1851WE. Background As part of the installation of a single point refueling system per STC SA1851WE, a motorized vent valve (gate type) is installed in each wing. The valve opens during the refueling operation to assure there is no pressure buildup in the wing tank. There is indication to the cockpit and refueling person that the valve is open but no indication that it completely closes at the completion of the refueling process. Valve closure is required to allow the fuel tank to pressurize under normal operation. This pressurization is required for fuel transfer in the event of a transfer pump failure. A repair station reported numerous failures of the subject vent valve. Upon further investigation, they discovered that the material of the o-rings in the valves was not compatible with fuel. When exposed to fuel, these o-rings swelled up causing the moving gate in the valve to bind, which burned out the electric motors. If the valve motor fails before the valve completely closes, there is no indication to either flight crew or refueling person, and the wing fuel tank (on the side with the burned out valve) may not pressurize properly.

2 Information The subject valves have o-rings that are designed for use in air and not fuel. If the gate in the valves bind or the motor fails and the valve doesn’t close completely, there may be no indication of loss of pressurization of the associated wing fuel tank. If a transfer pump subsequently fails, fuel from the wing tank will then be unavailable to the engine. Recommendations The FAA recommends that operators of aircraft with a single point pressure fueling system installed IAW STC SA1851WE, replace the existing o-rings in the refueling vent valve (2 valves per aircraft) with fuel-compatible o-rings in accordance with Rogerson ATS Service Bulletin 2554-28-01 within the next 100 hours or 1 year, whichever occurs first. For Further Information Contact Eric Smith, Los Angeles Aircraft Certification Office (LAACO), 3960 Paramount Blvd., Lakewood, CA 90712-4137; telephone: (562) 627-5260; email: [email protected]. For a copy of the Rogerson Service Bulletin 2554-28-01, contact: Rogerson Aircraft Corporation Phone (949) 660-0666 Customer Service Product Support Facility FAX (949) 442-2301 2201 Alton Parkway, Irvine, CA 92606 USA TELEX (910) 595-2840 SITA SNARGCR European Operators: Rogerson Customer Support Europe Phone 49-40-89-6990 Boschstrasse 23 FAX 49040-890-3014 D-2000 Hamburg, 50 Germany TELEX 213930