What was found
SMOKE IN COCKPIT SUDDENLY OCCURRED DURING CRUISE FLIGHT. SELECTED HUMIDIFIER OFF AND SMOKE DISSIPATED. *S/D* HEAVY CALCIUM DEPOSITS IN UNIT. SUSPECT SMOKE WAS ACTUALLY CALCIUM IN DUCTS. SHOP CLEANED AND CHECKED UNIT SERVICEABLE.
- 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
- Part
- Humidifier
- Condition
- Dirty
- Location
- Cockpit
- Component
- Lucas · M01AB0101
- Stage of operation
- CR
- Nature of condition
- B
- Precautionary procedure
- H
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.