A300
Flight Crew Air Transport Pilot (ATP)
Communication Breakdown
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; General Declared Emergency; General Maintenance Action
Aircraft; Procedure
During our enroute climb we received an Avionics Smoke Warning accompanied by the smell of fumes. We declared an emergency and got vectors to return to our departure airport. After landing we stopped on the runway for CFR to inspect for hot spots. When they found none we cleared runway and taxied to ramp parking where CFR inspected inside the aircraft for overheating avionics and/or lithium batteries in a shipping container. Preceding this event we had a deferral of the Field Limit Computer System 2 and the MEL did not direct us to pull the circuit breakers; thus power was applied to [the system which] caused overheating and fumes of the system 2 computer. I recommend that pulling circuit breakers should be written into the MEL.
An A300 flight crew declared an emergency and returned to their departure airport after receipt of an Avionics Smoke warning accompanied by the smell of electrical fumes. A circuit breaker involved with an associated system had not been pulled when deferred prior to departure.