APU overtemp on start resulting in tail fire. No APU fire warning.

Attributes
ACN	184748
Time
Date	199107
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : cvg
State Reference	OH
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : lhd
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	ground other : taxi other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 9000 flight time type : 2000
ASRS Report	184748
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 195 flight time total : 5540 flight time type : 1140
ASRS Report	184549
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other other : unspecified
Resolutory Action	flight crew : declared emergency flight crew : overcame equipment problem
Consequence	other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

The APU was on speed with normal indications so the right engine was shutdown. As the aircraft was being turned on to the gate lead in line there were radio calls to ground control that had a fire in the tail. Ground responded that they were calling the fire trucks. The APU exhaust gas temperature was high and rising. The captain ordered the first officer to shutdown the APU. No fire warning came on. The airplane was on the lead in line about 15 to 10 yds from the gate. The captain told the first officer they were going to evacuate/evacuation, intending the first officer advise the flight attendants to plan evacuate/evacuation out the front entrance and onto the jet bridge. The aircraft was still rolling and the captain was busy docking the aircraft to the jet bridge. The first officer then initiated the evacuate/evacuation command over the PA without concurrence from the captain. The captain ordered him to stop. Confirmation was obtained from ground control that no fire and smoke were visible. The captain made a PA to stop the evacuate/evacuation. By then 80 percent of the passengers had ground evacuated out of the aircraft using the slides. Supplemental information from acn 184549. As we proceeded more rapidly toward the gate stopping point, we heard more radio conversation about the flames coming out the tail of our airplane and about whether the fire trucks were sent. While distraction by the radio conversation, the first officer heard the captain say something to the effect of 'evacuate/evacuation the passengers.' as the airplane stopped, the first officer used the PA and said 'easy victor.' at this point the captain conveyed that's not what he wanted.

Original NASA ASRS Text

Title: APU OVERTEMP ON START RESULTING IN TAIL FIRE. NO APU FIRE WARNING.

Narrative: THE APU WAS ON SPD WITH NORMAL INDICATIONS SO THE R ENG WAS SHUTDOWN. AS THE ACFT WAS BEING TURNED ON TO THE GATE LEAD IN LINE THERE WERE RADIO CALLS TO GND CTL THAT HAD A FIRE IN THE TAIL. GND RESPONDED THAT THEY WERE CALLING THE FIRE TRUCKS. THE APU EXHAUST GAS TEMP WAS HIGH AND RISING. THE CAPT ORDERED THE FO TO SHUTDOWN THE APU. NO FIRE WARNING CAME ON. THE AIRPLANE WAS ON THE LEAD IN LINE ABOUT 15 TO 10 YDS FROM THE GATE. THE CAPT TOLD THE FO THEY WERE GOING TO EVAC, INTENDING THE FO ADVISE THE FLT ATTENDANTS TO PLAN EVAC OUT THE FRONT ENTRANCE AND ONTO THE JET BRIDGE. THE ACFT WAS STILL ROLLING AND THE CAPT WAS BUSY DOCKING THE ACFT TO THE JET BRIDGE. THE FO THEN INITIATED THE EVAC COMMAND OVER THE PA WITHOUT CONCURRENCE FROM THE CAPT. THE CAPT ORDERED HIM TO STOP. CONFIRMATION WAS OBTAINED FROM GND CTL THAT NO FIRE AND SMOKE WERE VISIBLE. THE CAPT MADE A PA TO STOP THE EVAC. BY THEN 80 PERCENT OF THE PAXS HAD GND EVACUATED OUT OF THE ACFT USING THE SLIDES. SUPPLEMENTAL INFO FROM ACN 184549. AS WE PROCEEDED MORE RAPIDLY TOWARD THE GATE STOPPING POINT, WE HEARD MORE RADIO CONVERSATION ABOUT THE FLAMES COMING OUT THE TAIL OF OUR AIRPLANE AND ABOUT WHETHER THE FIRE TRUCKS WERE SENT. WHILE DISTR BY THE RADIO CONVERSATION, THE FO HEARD THE CAPT SAY SOMETHING TO THE EFFECT OF 'EVAC THE PAXS.' AS THE AIRPLANE STOPPED, THE FO USED THE PA AND SAID 'EASY VICTOR.' AT THIS POINT THE CAPT CONVEYED THAT'S NOT WHAT HE WANTED.

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.