Narrative:

As we taxied into position on the runway; two following flights reported that significant flames and smoke were coming from our APU compartment. We verified the APU had shut down; exited the runway; and requested crash fire rescue equipment support. The QRH provided no guidance given the lack of ECAM indications; and I elected to deploy the APU fire extinguishing system as a precaution. Once we were able to communicate with the crash fire rescue equipment crews on a discreet emergency frequency; we determined that the event was over. We returned to the gate and debriefed with the crash fire rescue equipment and cabin crews.

Google
 

Original NASA ASRS Text

Title: The flight crew of an A320 was alerted by other aircraft of significant smoke and flames emanating from their APU while taking the departure runway. The Captain activated the APU Fire Extinguishing system and contacted the CFR personnel; determined the event was over; and returned the aircraft to the gate followed by a crew briefing.

Narrative: As we taxied into position on the runway; two following flights reported that significant flames and smoke were coming from our APU compartment. We verified the APU had shut down; exited the runway; and requested CFR support. The QRH provided no guidance given the lack of ECAM indications; and I elected to deploy the APU fire extinguishing system as a precaution. Once we were able to communicate with the CFR crews on a discreet emergency frequency; we determined that the event was over. We returned to the gate and debriefed with the CFR and cabin crews.

Data retrieved from NASA's ASRS site as of July 2013 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.