MD-11
Flight Crew Last 90 Days 25; Flight Crew Total 6700; Flight Crew Type 2700
Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Flight Crew Overcame Equipment Problem
Aircraft
During cruise; the avionics compartment fan turned on and we experienced a mild strange odor and an associated thud. We contacted Maintenance Control via Satcom and they concurred that we should pull the avionic compartment fan circuit breaker as a precaution. Maintenance Control; Dispatch; and us as a crew; decided it was the proper course of action. Within minutes of pulling the breaker; the acrid odor was dissipated. We continued without further incident and the aircraft discrepancy was documented in the logbook.
At cruise we detected an electrical burning smell. We suspected the avionics cooling fan. We wanted to act quickly before the situation got worse so we immediately contacted Maintenance Control and Dispatch to confirm with them that pulling the Circuit Breaker (CB) was the correct course of action. After pulling the CB the smell went away quickly. Our decision making was hindered by the lack of information presented in the systems manual on the number of fans in operation in the avionics bay and the related CB's. After pulling the CB we looked in the MEL for the avionics fan and it does not even have a Dispatch Maintenance Procedure (DMP). The systems manual seems to indicate we have 4 fans but the CB panel and MEL seem to indicate 5 fans. Please follow up with me and let me know if the fan indeed was on its way to a bad end.
MD11 flight crew detects an electrical burning smell during cruise at FL370 and suspects the avionics cooling fan. Maintenance Control is consulted and the fan circuit breaker is pulled and the smell quickly dissipates. Flight continues to destination.