# SDR ASAA2021030434248

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: March 4, 2021
- Submitted: March 9, 2021
- Operation: Air carrier
- Aircraft: [N433AS](https://openairdocs.org/aircraft/N433AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 41704
- Aircraft time: 27,913 hours, 8,915 cycles
- System (JASC): [3442 · Weather Radar System](https://openairdocs.org/jasc/3442)
- Part: Drive Unit
- Part number: 6225135822
- Part serial: 40F853
- Condition: Faulted
- Location: Wx Radar Antenna
- Part time: 24,970 hours, 7,399 cycles
- Stage of operation: NR
- How discovered: 9
- Nature of condition: O
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2021030434248

## Discrepancy

RADAR SHOWED FALSE RETURNS IN AUTO MODE ONLY. RETURNS WERE FROM 9 O'CLOCK TO 11 O'CLOCK POSITION 40 TO 80 MILES. GROUNDED - YES. DUE TO HISTORY, REMOVED AND REPLACED WEATHER RADAR ANTENNA DRIVE UNIT REF B737-900 AMM 34-43-11. PERFORMED OPERATIONAL TEST OF WEATHER RADAR SYSTEM REF AMM 34-43-00-710-802-001. OP CHECK GOOD. ETOPS GROUND VERIFICATION SUCCESSFUL.

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