# SDR DALA2019112906962

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: November 29, 2019
- Submitted: November 29, 2019
- Operation: Air carrier
- Aircraft: N972DL
- Make and model: Doug MD-88
- Registry model: [Doug MD-88](https://openairdocs.org/model/mcdonnell-douglas-md-88) (OpenAirDocs)
- Aircraft serial: 53215
- Aircraft time: 75,028 hours, 55,563 cycles
- System (JASC): [2910 · Hydraulic System, Main](https://openairdocs.org/jasc/2910)
- Part: Check Valve
- Condition: Bypassing
- Location: Hyd System
- Stage of operation: NR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/DALA2019112906962

## Discrepancy

SHIP 972 - ATB - DUE TO NLG FAILED TO RETRACT, EXTENDED THE MLG AND RETURNED TO ATL, NO EMERGENCY DECLARED. CORRECTIVE ACTION. TROUBLESHOOTING IN PROGRESS. RESTRICTOR VALVE NO HELP. C/W NO-GO ODI PREVENTION. FOUND UPPER SIDE CHECK VALVE BYPASSING ON NLG HYDRAULIC SYSTEM T-FITTING. REPLACED UPPER CHECK VALVE. NOW CHECKS GOOD. SDR REPORTED DUE TO FACT THAT THE MCC NOTIFICATION MENTIONED A DECLARED EMERGENCY. (LP5428112)

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