B737 Next Generation Undifferentiated
Maintenance Airframe; Maintenance Powerplant
Situational Awareness
Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
General Maintenance Action
Aircraft
Aircraft X encountered a smoke/odor/fume event during landing at ZZZ for smoke and a strong electrical burning smell in the aft galley. The aircraft flight crew requested airport emergency equipment assistance after landing. The aircraft was taken out of service for troubleshooting. Several items and components were evaluated including coffeemakers and galley lighting ballasts and wiring. Ultimately ZZZ aircraft Maintenance discovered that the aft door heater had overheated and tripped open circuit breaker X1234 (D7 on the P91 PDP-1 panel). The heater intake was found clogged with FOD and debris. The debris appeared to be tape from overhead air distribution ducting and gasper vent ducting. There also appeared to be material from overhead bin structure. Suspect that the air distribution duct and gasper ventilation ducts accumulated debris from years of operation. Some the debris also appeared to have been relatively new and may have been dislodged from recent Maintenance operations. These operations may have included reconfiguration of the cabin during modification; or displacement of the overhead bins and ventilation ducting during installation. If one aircraft experienced this event; there is a strong possibility that other aircraft maybe developing a condition of FOD and debris in the air distribution ducting. To proactively prevent similar events all B737NG aircraft should be examined and inspected for FOD and debris accumulation in the overhead air distribution ducting and gasper vent ducting.
B737NG Mechanic reported a fume event possibly caused by debris in air distribution ducting.