Incident Overview
During cruise flight, an electrical fire erupted in the circuit board and electrical components of the temperature control unit for the rear galley oven. The associated circuit breaker opened, and electrical power to the galley was turned off. Within minutes, the unit was cool to the touch. The flight crew subsequently performed an unscheduled landing.
Sequence of Events
The fire originated in the circuitry of the oven temperature control unit. Upon activation of the circuit breaker, power was isolated, allowing the overheated components to cool. The aircraft continued to operate normally after the power interruption, and the landing was completed without further incident. The manufacturer of the unit is reportedly no longer in business.
Maintenance Background
The airline reported that this type of failure has been a chronic problem. On December 7, 1984, the airline began to retrofit the remaining units with a circuit modification. The overheated oven temperature control circuitry is enclosed in a metal box, which contained the fire and prevented further damage.