# SDR IPXA2026032793659

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: March 26, 2026
- Submitted: March 27, 2026
- Operation: Air carrier
- Aircraft: [N634UP](https://openairdocs.org/aircraft/N634UP), registered now
- Make and model: Boeing 747-8F
- Registry model: [Boeing 747-8F](https://openairdocs.org/model/boeing-747-8f) (OpenAirDocs)
- Aircraft serial: 37564
- Aircraft time: 35,865 hours, 5,324 cycles
- System (JASC): [2120 · Air Distribution System](https://openairdocs.org/jasc/2120)
- Part: Valve
- Part number: 4528A010001
- Part serial: 452801253
- Condition: Faulted
- Location: Zone 100
- Stage of operation: IN
- How discovered: V
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/IPXA2026032793659

## Discrepancy

AIR TURN BACK ONCE AIRBORNE F/D, U/D & C/R TEMP UNCONTROLLABLE IN AUTO OR MANUAL MODE. NO MAGENTA REF. TEMP SETTINGS WERE DISPLAYED. TEMP IN F/D VARIED FROM 63F TO 87F. CREW REST DROPPED TO 50F. ATB ACCOMPLISHED. SEE BARCODE T3F18E008JN5Z. R AND R UD TRIM AIR VALVE IAW AMM 21-61-10. OPS CHECK GOOD.

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