# SDR 99UAL900061

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 24, 1999
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: N178UA
- Make and model: Boeing 747422
- Aircraft serial: 24385
- Engine: Pwa PW4056
- System (JASC): [2170 · Humidity Control System](https://openairdocs.org/jasc/2170)
- Part: Humidifier
- Condition: Smoking
- Location: Cockpit
- Stage of operation: CR
- Nature of condition: B
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/99UAL900061

## Discrepancy

SMOKE IN COCKPIT SUDDENLY OCCURRED DURING CRUISE FLIGHT.  SELECTED HUMIDIFIER OFF AND SMOKE DISSIPATED.

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