Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe
Aircraft Automation Overrode Flight Crew; General Evacuated; General Maintenance Action
Aircraft
About 12 minutes prior to departure; approximately one minute after switching from external power to APU power; APU auto shutdown. APU FIRE Light illuminated with EICAS APU FIRE warning; FIRE BELL and FIRE BOTTLE auto discharge. Ground Control was contacted for CFR to respond and passenger deplaned right away via jet bridge. No fire (per CFR). Maintenance performed inspection; MELed APU and we departed. Upon switching to external power [after arrival]; APU FIRE Light illuminated with EICAS APU FIRE warning and FIRE BELL. Ground Control contacted to inform of situation and for CFR to respond. Operations and Maintenance also contacted. No Fire. Maintenance then took aircraft. There is nothing that we could do to change this. Maintenance [at the departure airport] said that a spike in a power card (or something like that) was the cause. We would not assume anything after arrival and it was absolutely required to call CFR. We also had no fire bottle at that time.
Widebody First Officer experiences an APU fire warning with auto shut down and fire bottle discharge during preflight. The passengers are evacuated through the jet bridge; but CFR finds no evidence of fire. The APU is MEL'ed and the flight departs for North America. Upon gate arrival; with the APU off and switching to ground power; the scenario repeats.