# SDR CALA2023092902907

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 27, 2023
- Submitted: September 29, 2023
- Operation: Air carrier
- Aircraft: [N24972](https://openairdocs.org/aircraft/N24972), registered now
- Make and model: Boeing 787-9
- Registry model: [Boeing 787-9](https://openairdocs.org/model/boeing-787-9) (OpenAirDocs)
- Aircraft serial: 40939
- Aircraft time: 26,002 hours, 2,442 cycles
- System (JASC): [2300 · Communications System](https://openairdocs.org/jasc/2300)
- Part: Sdu
- Part number: 8223057101
- Part serial: 1715
- Condition: Unknown
- Location: Sat Com
- Part time: 24,833 hours, 2,344 cycles
- Stage of operation: CR
- How discovered: O
- Nature of condition: O, S
- Precautionary procedure: A, D, O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CALA2023092902907

## Discrepancy

SAT VOICE LOST ADVISORY SATCOM VOICE COMMUNICATION IS LOST (NO SIGNAL/RECEPTION) DUE TO AIRCRAFT MANEUVERING, LOW ELEVATION ANGLES/BLOCKAGE TO THE SATEL LITE OR WHILE FLYING IN A POLAR ROUTE. WHEN AN AIRPLANE IS IN CR UISE MODE, THEN THE MESSAGE IS DELAYED BY 60SECS, OTHERWISE IN . FOUND MX MESSAGE 23-19407 SATELLITE, UNIT OFF 79-2329-9-0001 1715 ON 79-2329-9-0001 0040 SATELLITE, UNIT OFF 79-2329-9-0001 1715 ON 0000 T/S PER FIM TASK DMC-B787-A-23-10-F5-04A-421A-A FOR MX MESSAGE 23-19407. NO FAUTLS FOUND UNABLE TO DUPLICATE INDICATED FAULT. WIRING CHECKS PER FIM TASK ALSO GOOD. PER TECH SUPPORT UPDATE REMOVED AND REPLACED SATCOM SDU AS PRECAUTINARY PER AMM 23-15-10. ADJ/TEST SATISFACTORY. SYSTEM OK FOR SERVICE.

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