# SDR QKPR06009

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 18, 2006
- Submitted: December 19, 2006
- Operation: General aviation
- Filed by: [Piedmont Aviation Component Services, LLC, repair station QKPR504X](https://openairdocs.org/faa-repair-station/QKPR504X/piedmont-aviation-component-services-llc.md) (OpenAirDocs)
- Make and model: Doug A4D
- System (JASC): [4930 · APU Engine Fuel and Control](https://openairdocs.org/jasc/4930)
- Part: Fuel Control
- Part number: 38828406
- Part serial: A397C
- Condition: Leaking
- Location: Apu
- Component: Apu, Honeywell, GTCT36150RR
- Component part number: 38005141112
- Stage of operation: NR
- How discovered: 9
- Nature of condition: O
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/QKPR06009

## Discrepancy

FUEL PRESSURE IN THE DIFFERENTIAL PRESSURE VALVE IS CAUSING SEVERE PITTING INSIDE THE FCU HOUSING.  THIS PITTING EVENTUALLY BECOMES A PIN HOLE IN THE HOUSING. THIS PIN HOLE ALLOWS A STREAM OF FUEL, AT IDLE AND WHEN PRESSURE IS APPLIED, TO EXIT THE FCU. POTENTIALLY, IF THIS PROBLEM IS NOT CORRECTED IT COULD CREATE A FIRE HAZARD.  * REMOVE AIRCRAFT INFORMATION.

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