20100814040749I

Incident narrative received a telephone call on 08-14-2010 at about 1230 from the Chicago O'Hare flight standards district office manager. The manager stated that an emergency evacuation of a united airlines A-320 aircraft had occurred due to the possibility of an aft cargo pit fire/smoke. Details of the incident at that time were not clear so he asked if I would respond to the scene and investigate the incident. The regional operations center shortly afterwards sent to the district office an incident report with the following information:"ord: ual 611, N449UA, A320, lga to ord, landed ord and began deplaning at gate B-14, when a cargo area fire warning indication was received, after which, 40 passengers were deplaned via the chutes (slides) resulting in 4 minor injuries. No fire was found. POB: 144, injuries: 4 minor, 8/14 1529Z."on arrival at the scene noted that maintenance had removed the deflated slides and was in the process of moving the aircraft to the united airlines service center hangar for further inspection and repairs. At that time the united airlines management team was also in conference at the station operations center discussing all issues related to the emergency evacuation incident. I was able to sit in for about the last third of the conference. One of the incident facts that was later clarified with a city of Chicago operations manager that was at the scene was the number of injuries. The manager stated that there were 6 reported minor (green) injuries of which 5 were passengers and 1 was a united airlines employee. All of those individuals refused treatment and no one went to the hospital. Further details of the evacuation are as follows: the evacuation was initiated several minutes after the aircraft taxied into the gate was about to off load the passengers, and the ramp ground personnel had just started to off load the cargo compartment baggage. At about that time the flight deck crew received an aft cargo compartment smoke and fire indication on their display panels. The fire extinguisher was then discharged into cargo compartments and an emergency evacuation of the aircraft was initiated. On board were 144 passengers with 2 flight deck crew and 3 cabin crew. 42 passengers evacuated through the escapes slides. Those were as follows: 35 passengers through the slide at door 1-right, 5 passengers through the slide at door 2-right and 2 passengers through the slide at door 2-left. The rest of the 102 passengers and 5 aircraft crew members left the aircraft through the open door 1-left into the jetaway which was in place at that time. At the present time united airlines maintenance has replaced the 3 door slide, the discharged fire extinguisher and the cargo compartment smoke detectors. Troubleshooting continues to determine the cause of the smoke and fire indication. Maintenance has also stated that they have so FAR, found no evidence that any fire occurred in the aft cargo compartment and the aircraft had no history of previous fire or smoke indication problems. Note: a terminal gate security video of the incident exists and is in the possession of united airlines. This investigation continues.a followup check was conducted on August 17, 2010 at the united airlines service center hangar. It was noted that the work on aircraft N449UA had been completed and the aircraft had been released for service and was currently flying.a review of the computer log records indicated that maintenance had found no evidence of fire or overheat in the aft cargo compartment during their inspections and troubleshooting and found nothing wrong with the fire and smoke detection warning system on the aircraft. The final fix included the replacement of the 3 evacuation slides that had been inflated, the replacement of the aft cargo compartment fire extinguishing bottle and the replacement of 4 aft cargo compartment smoke detectors.