# SDR 2010FA0000029

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 9, 2009
- Submitted: January 15, 2010
- Operation: General aviation
- Aircraft: [N3875C](https://openairdocs.org/aircraft/N3875C), registered now
- Make and model: Cessna 421C
- Registry model: [Cessna 421C](https://openairdocs.org/model/cessna-421c) (OpenAirDocs)
- Aircraft serial: 421C0127
- System (JASC): [3230 · Landing Gear Retraction/Extension System](https://openairdocs.org/jasc/3230)
- Part: Control Valve
- Part number: 99102251
- Part serial: 758
- Condition: Cracked
- Location: Landing Gear
- Part time: 16 hours
- Stage of operation: IN
- How discovered: 9
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2010FA0000029

## Discrepancy

DURING AN ANNUAL INSP, A HAIRLINE CRACK WAS DISCOVERED ON THE BLOCK OF THE LANDING GEAR CONTROL VALVE, PN 9910225-1.  THE CRACK WAS ALLOWING HYD FLUID TO LEAK OUT, THE LEAK WAS SMALL.  THE PART HAD 16.1 HRS SINCE O/H.  THE VALVE WAS SENT BACK TO O/H, WHERE THE BLOCK WAS REPLACED UNDER WARRANTY, NO EXPLANATION WAS GIVEN FOR THE CRACK, THE WARRANTIED PART WAS INSTALLED AND WORKED AS DESIGNED.

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