# SDR CALA2026082618926

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 23, 2026
- Submitted: August 26, 2026
- Operation: Air carrier
- Aircraft: [N228UA](https://openairdocs.org/aircraft/N228UA), registered now
- Make and model: Boeing 777222
- Aircraft serial: 30556
- Aircraft time: 95,865 hours, 11,288 cycles
- Engine: Pwa PW4090
- System (JASC): [3400 · Navigation System](https://openairdocs.org/jasc/3400)
- Part: Adiru
- Part number: HG2060AD01
- Part serial: 386
- Condition: Faulted
- Location: Zone 100
- Part time: 31,816 hours, 4,751 cycles
- Stage of operation: CL
- 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/CALA2026082618926

## Discrepancy

TCAS FAIL, BOTH CHANNELS. DEBRIEF WITH CREW, TCAS FAILED AT 15000 FT, CREW PUT IN ALT, 1 & 2, NO HELP.  NO MSSG AT THIS TIME.  TCAS STATUS MESSAGE PRESENT, NOT ACTIVE ON MAT. FAULT INTERMITTANT IAW FIM 34-21 TASK 848.  RECOMMEND REPLACE ADIRU IAW FIM DUE TO HISTORY.  R & R AIR DATA INERTIAL REFERENCE UNIT IAW AMM 34-21-01.  PERFORMED SOFTWARE LOAD ON NEW ADIRU IAW AMM 34-21-01-420-801.  VERIFIED OPS CHK & OPS SOFTWARE CORRECT. PERFORMED TCAS GROUND TEST IAW AMM 34-45-00-740-801. OPS CHKD GOOD. PERFORMED TCAS COMPUTER BITE ON TCAS BOX, NO FAULTS. STATUS MESSAGE CLEARED ITSELF & DID NOT RETURN DURING OPS CHECKS.  NO FURTHER FAULTS PRESENT. OPS CHKD TCAS AND ADIRU GOOD.

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