# SDR AALA202303149395

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: March 7, 2023
- Submitted: March 14, 2023
- Operation: Air carrier
- Aircraft: [N170US](https://openairdocs.org/aircraft/N170US), registered now
- Make and model: Airbus A320*
- Aircraft serial: 1462
- Aircraft time: 70,084 hours, 26,840 cycles
- System (JASC): [3240 · Landing Gear Brake System](https://openairdocs.org/jasc/3240)
- Part: Pump
- Part number: 3031863001
- Part serial: MX729813
- Condition: High Pressure
- Location: Zone 400 - Nac/P
- Part time: 37,628 hours, 17,579 cycles
- Stage of operation: TX
- How discovered: O
- Nature of condition: O
- Precautionary procedure: D
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/AALA202303149395

## Discrepancy

AIRCRAFT WAS GROUNDED: ON TAXI OUT AND APPLYING BRAKES, BRAKES PULSED MODERATELY. FLIGHT ATTENDANTS REPORT UNUSUAL NOISE AND KNOCKING SOUND. **SUPPLEMENTAL REPORT FOR AALA202303139395: DURING A REVIEW OF THE FOQA DATA IT WAS NOTED THAT THE #1 ENGINE DRIVEN HYDRAULIC PUMP WAS PRODUCING APROXIIMATLEY 120 PSI GREATER THAN THE AMM LIMITS AND THE #2 ENGINE DRIVE HYDRAULIC PUMP WAS PRODUCING RIGHT AROUND THE MINIMUM PRESSURE. MAINTENANCE REPLACED THE #1 AND #2 (AALA202303140003) ENGINE HYDRAULIC PUMPS PER AMM 29-11-51. A SATISFACTORY LEAK / OPERATIONAL CHECK WAS ACCOMPLISHED.  ** (CLOSED)

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.