# SDR ASAA2022021937503

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 19, 2022
- Submitted: February 23, 2022
- Operation: Air carrier
- Aircraft: [N479AS](https://openairdocs.org/aircraft/N479AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 60576
- Aircraft time: 23,328 hours, 7,365 cycles
- System (JASC): [3040 · Windshield/Door Rain/Ice Removal](https://openairdocs.org/jasc/3040)
- Part: Control Unit
- Part number: 8300005605
- Part serial: 24300
- Condition: Intermittent
- Location: E/E Rack E4-2
- Part time: 22,274 hours, 7,090 cycles
- Stage of operation: AP
- How discovered: V
- Nature of condition: M
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2022021937503

## Discrepancy

LEFT SIDE WINDOW HEAT "OVERHEAT" ON FINAL APPROACH. TRIED ONE 5 MIN RESET IN AIR AND DID NOT RESET. GROUNDED - YES. COULD NOT DUPLICATE, CKD TEMP SENSOR & HEAT FILM RESISTANCE AND TAP SETTING, ALL CKD NML. R/R WHCU PER B737-900 AMM 30-41-11. SYS OPS CKS NML PER SAME AND AMM 30-41-00. GROUND VERIFICATION SUCCESSFUL.

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