# SDR MJ12001F00000

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: June 7, 2001
- Submitted: August 8, 2001
- Operation: Air carrier
- Aircraft: [N633DS](https://openairdocs.org/aircraft/N633DS), registered now
- Make and model: Lear 35A
- Registry model: [Lear 35A](https://openairdocs.org/model/gates-learjet-35a) (OpenAirDocs)
- Aircraft serial: 362
- System (JASC): [2810 · Fuel Storage](https://openairdocs.org/jasc/2810)
- Part: Flapper Valve
- Part number: S461
- Condition: Defective
- Location: Wing Tip Tank
- Part time: 139 hours
- Stage of operation: NR
- How discovered: O
- Nature of condition: K
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/MJ12001F00000

## Discrepancy

FLAPPER VALVE SEAL PN S-461 FOR LEFT AND RIGHT WING TIP TANKS WERE INSTALLED IAW SB 35/36-28-10 ON 02/19/01  AIRCRAFT HOURS 8,167.3 CUSTOMER ARRIVED AT OUR FACILITY ON 06/04/2001 AIRCRAFT HOURS 8306.9 WITH REPORTED DISCREPANCY AS FOLLOW:  INVESTIGATE TIP TANK FLAPPER VALVES BYPASSING FUEL.  INVESTIGATION REVEALED LEFT AND RIGHT TIP TANK TO WING FLAPPER VALVES FORWARD AND AFT POSITIONS PN S-461 WERE SWOLLEN AND DEFORMED PERMITTING FUEL FROM WING TO BYPASS INTO THE TIP TANKS.

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