Narrative:

On may/fri/00, we arrived at our gate and ground power was plugged in. We had a good gpu available light, the power select switch was selected from battery to external power. The system depowered and the gpu available light went out. The power select switch was selected back to battery. The airplane was shut down per our shutdown checklist (power select switch off). Station personnel said the gpu had problems and was just fixed. The crew left the airplane. On may/sat/00, during preflight inspection we noted the area around the gpu receptacle had been scorched. Ground personnel said the gpu plug caught on fire. Apparently the gpu was left on and plugged in. A contract mechanic checked the system and signed it off. We flew to ZZZ. Arriving at the gate in ZZZ, ground power as plugged in. We had a good gpu available light and a normal 28 volt reading. We set brakes and shut down the airplane per the checklist and left the power select switch on external power (normal practice). We notified our maintenance controller of another minor discrepancy and suggested the mechanic also take a look at the gpu receptacle. We left the airplane. Later on I was notified that the airplane caught fire again at the gpu plug. Significant damage was reported. Callback conversation with reporter revealed the following information: the reporter stated the exact cause of the ground power fault is unknown but maintenance suspects the ground power control unit. The reporter said the contract technician at XXX who investigated the first report did not appear to have the knowledge of the embraer 120 electrical system. The reporter said the technician cleaned the plug and inspected the back of the external power panel and cleared the logbook. The reporter stated the airplane should have been grounded at this time.

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Original NASA ASRS Text

Title: AN EMBRAER 120 PARKED ON GATE WITH GPU POWERING ACFT THE GND PWR PLUG CAUGHT FIRE. LATER IN THE DAY GND PWR PLUG AGAIN CAUGHT FIRE INCURRING MAJOR ACFT DAMAGE. CAUSE A SUSPECT GND PWR CTL PANEL.

Narrative: ON MAY/FRI/00, WE ARRIVED AT OUR GATE AND GND PWR WAS PLUGGED IN. WE HAD A GOOD GPU AVAILABLE LIGHT, THE PWR SELECT SWITCH WAS SELECTED FROM BATTERY TO EXTERNAL PWR. THE SYS DEPOWERED AND THE GPU AVAILABLE LIGHT WENT OUT. THE PWR SELECT SWITCH WAS SELECTED BACK TO BATTERY. THE AIRPLANE WAS SHUT DOWN PER OUR SHUTDOWN CHKLIST (PWR SELECT SWITCH OFF). STATION PERSONNEL SAID THE GPU HAD PROBS AND WAS JUST FIXED. THE CREW LEFT THE AIRPLANE. ON MAY/SAT/00, DURING PREFLT INSPECTION WE NOTED THE AREA AROUND THE GPU RECEPTACLE HAD BEEN SCORCHED. GND PERSONNEL SAID THE GPU PLUG CAUGHT ON FIRE. APPARENTLY THE GPU WAS LEFT ON AND PLUGGED IN. A CONTRACT MECH CHKED THE SYS AND SIGNED IT OFF. WE FLEW TO ZZZ. ARRIVING AT THE GATE IN ZZZ, GND PWR AS PLUGGED IN. WE HAD A GOOD GPU AVAILABLE LIGHT AND A NORMAL 28 VOLT READING. WE SET BRAKES AND SHUT DOWN THE AIRPLANE PER THE CHKLIST AND LEFT THE PWR SELECT SWITCH ON EXTERNAL PWR (NORMAL PRACTICE). WE NOTIFIED OUR MAINT CTLR OF ANOTHER MINOR DISCREPANCY AND SUGGESTED THE MECH ALSO TAKE A LOOK AT THE GPU RECEPTACLE. WE LEFT THE AIRPLANE. LATER ON I WAS NOTIFIED THAT THE AIRPLANE CAUGHT FIRE AGAIN AT THE GPU PLUG. SIGNIFICANT DAMAGE WAS RPTED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE EXACT CAUSE OF THE GND PWR FAULT IS UNKNOWN BUT MAINT SUSPECTS THE GND PWR CTL UNIT. THE RPTR SAID THE CONTRACT TECHNICIAN AT XXX WHO INVESTIGATED THE FIRST RPT DID NOT APPEAR TO HAVE THE KNOWLEDGE OF THE EMBRAER 120 ELECTRICAL SYS. THE RPTR SAID THE TECHNICIAN CLEANED THE PLUG AND INSPECTED THE BACK OF THE EXTERNAL PWR PANEL AND CLRED THE LOGBOOK. THE RPTR STATED THE AIRPLANE SHOULD HAVE BEEN GROUNDED AT THIS TIME.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.