# SDR IPXA2019072544878

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 23, 2019
- Submitted: July 26, 2019
- Operation: Air carrier
- Aircraft: [N577UP](https://openairdocs.org/aircraft/N577UP), registered now
- Make and model: Boeing 747-44AF
- Registry model: [Boeing 747-44AF](https://openairdocs.org/model/boeing-747-44af) (OpenAirDocs)
- Aircraft serial: 35666
- Aircraft time: 41,349 hours, 6,115 cycles
- System (JASC): [3445 · Air Collision Avoidance System](https://openairdocs.org/jasc/3445)
- Part: Computer
- Part number: 751790010020
- Part serial: 2045749
- Condition: Malfunctioned
- Location: Tcas
- Stage of operation: TO
- How discovered: O
- Nature of condition: O
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/IPXA2019072544878

## Discrepancy

INSPECTION TYPE:N/A ATB- XPNDR 1 IN TA/RA SHOWED TCAS OFF, SWITCHED TO XPNDR 2 IN TA/RA SHOWED TCAS OFF. ATC COULD NOT SEE US. CYCLED BACK AND FORTH SEVERAL TIMES IT DID NOT WORK.NO FAULT FOUND. OPS TEST PER AMM 34-45-00-715-001-004 TEST OK . R/R TCAS COMPUTER PER AMM 34-45-01. OPS TEST OK. EFF SOURCE REF: IPC 34-45-01-02B-020K.

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