Flight Crew Air Transport Pilot (ATP)
Time Pressure
Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor; Ground Event / Encounter Other / Unknown
Flight Crew Took Evasive Action; General Declared Emergency; General Flight Cancelled / Delayed; General Maintenance Action
Aircraft
During first flight of the day preflight the aircraft was powered using a GPU. All required systems were then powered up including the air conditioner. During the preflight walk around the Captain noticed a strange odor coming from the rear baggage compartment area. The Captain notified the First Officer of the odor and asked for help in identifying where the odor was coming from. Upon inspection it was found that the AC compressor was sparking with smoke beginning to flow from the unit. The air conditioner was immediately turned off at which time it caught fire. The cockpit halon fire extinguisher was then used to put the fire out and the Fire Department was called. The Fire Department arrived and determined the fire was indeed extinguished and remained on site until the AC unit cooled.
During preflight; GPU and AC on; I observed sparks emanating from AC unit while inspecting aft equipment bay. The sparks were faint; so I asked my partner to have a look as well. While he was observing the AC unit; I began to see smoke developing from the lower vent area. I ran to turn the AC unit off. According to my partner; it was then that flames erupted from the AC. As I was returning to the rear of the plane; my partner yelled to me that we had a fire. I immediately returned to the cockpit to secure the fire extinguisher. He met me at the wingtip and took the extinguisher to the fire. He suppressed the fire and I instructed ground personnel to call fire rescue. GPU and Battery power were removed from aircraft. The firefighters arrived on scene and utilizing thermal imaging equipment determined that no fire threat remained. I notified the on duty Assistant Chief Pilot and advised him of the situation. I conferred with Maintenance personnel on the details of the subsequent write up and they agreed that the wording covered the episode and any necessary maintenance which might be required.
A Citation 560 air conditioning compressor caught fire during preflight on ground power at the gate; the flight crew extinguished the fire using the aircraft's walk around halon bottle.