Narrative:

Upon arrival at dtw and after clearing the runway 21R I advised the first officer that because we were so 'light,' I was having to constantly apply the brakes to control taxi speed. We would be shutting down the right engine. I observed the air conditioning pack was shut down and I moved the fuel cutoff toward the off position. The left reverser light was still illuminated. Because of the ever present construction projects I surveyed the taxiway for foreign objects. Satisfied that no foreign objects were present I began cycling the reverser to solve this new problem. The light went out after several attempts. The first officer informed me we would need the APU as the ground power was reported inoperative. I directed him to start the APU. It was reaching operation as we were entering the area adjacent to the concourse. APU operation appeared normal but my attention was fully engaged attempting to analyze the maneuver required to park in this highly congested area. The parking maneuver would require my wing to pass under a DC10 wing and my wingtip appeared very close to the DC10 engine nacelle. The lighting in the gate area was not very well focused and seemed to shine mostly in my windshield. I stopped the aircraft and dimmed all my flight and engine panel lights to aid in outside observation. Finally arriving at the gate I set the brakes and shut down the left engine. As we were beginning the parking checklist, there was a loud banging on the nose. The agent was signalling the external power was now available. I checked the volts/frequency and after beginning the cooling process on the APU I selected the external power supply. There was a momentary hesistancy for the left buss to accept power. I observed that both the left and right busses appeared powered. I then attempted to reconfirm that the chocks were in. Unable to attract an agent's attention I left the brakes set and called for the parking checklist. We were on a tight schedule and already behind due to the problems in cle. I desired to retrieve the flight releases as soon as possible and after the last of the passenger deplaned I left the aircraft. The first officer filled out the times and fuel log. I left the jetway via the exterior stairs, proceeded to operations and immediately returned when my preflight duties were completed. Upon my return I was advised that I needed to go to the ticket podium to talk to 'them' about the engine running? I assumed it had something to do with the reverser unlocked problems we had experienced. I didn't find anyone in particular so I returned to the cockpit. I began preflight duties and a few mins later the maintenance supervisor arrived. He sat down and asked me why I had left the aircraft with an engine running? I was flabbergasted. I asked what he meant and he explained to me that the line mechanic had shut down the right engine. I was completely dumbfounded. How could I have committed such egregious transgression. I spoke with the maintenance staff and assured them I was fully aware of the potential for disaster. I can only surmise that my attention was so distracted by the ongoing events that the right engine was not shut down on taxi in. The mechanic was not sure if the fuel control was in the full on position or partially off. My normal checklist routine was interrupted several times particularly by the attempts to reconfirm the chocks were in. I have in the past experienced erroneous chock indications. So at busy congested areas I often double check the chocks. As I was unable to reconfirm the chocks I left the brakes set. However I still do not understand how I could have perceived the APU or the external electrical power system powering the right AC buss. The right engine generator should have maintained priority. I did not observe anything out of the ordinary in regards to the electrical system operation.

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Original NASA ASRS Text

Title: PIC LEAVES AIRPLANE UNATTENDED WITHOUT REALIZING THE RT ENG IS RUNNING.

Narrative: UPON ARR AT DTW AND AFTER CLRING THE RWY 21R I ADVISED THE FO THAT BECAUSE WE WERE SO 'LIGHT,' I WAS HAVING TO CONSTANTLY APPLY THE BRAKES TO CTL TAXI SPD. WE WOULD BE SHUTTING DOWN THE R ENG. I OBSERVED THE AIR CONDITIONING PACK WAS SHUT DOWN AND I MOVED THE FUEL CUTOFF TOWARD THE OFF POS. THE L REVERSER LIGHT WAS STILL ILLUMINATED. BECAUSE OF THE EVER PRESENT CONSTRUCTION PROJECTS I SURVEYED THE TXWY FOR FOREIGN OBJECTS. SATISFIED THAT NO FOREIGN OBJECTS WERE PRESENT I BEGAN CYCLING THE REVERSER TO SOLVE THIS NEW PROB. THE LIGHT WENT OUT AFTER SEVERAL ATTEMPTS. THE FO INFORMED ME WE WOULD NEED THE APU AS THE GND PWR WAS RPTED INOP. I DIRECTED HIM TO START THE APU. IT WAS REACHING OP AS WE WERE ENTERING THE AREA ADJACENT TO THE CONCOURSE. APU OP APPEARED NORMAL BUT MY ATTN WAS FULLY ENGAGED ATTEMPTING TO ANALYZE THE MANEUVER REQUIRED TO PARK IN THIS HIGHLY CONGESTED AREA. THE PARKING MANEUVER WOULD REQUIRE MY WING TO PASS UNDER A DC10 WING AND MY WINGTIP APPEARED VERY CLOSE TO THE DC10 ENG NACELLE. THE LIGHTING IN THE GATE AREA WAS NOT VERY WELL FOCUSED AND SEEMED TO SHINE MOSTLY IN MY WINDSHIELD. I STOPPED THE ACFT AND DIMMED ALL MY FLT AND ENG PANEL LIGHTS TO AID IN OUTSIDE OBSERVATION. FINALLY ARRIVING AT THE GATE I SET THE BRAKES AND SHUT DOWN THE L ENG. AS WE WERE BEGINNING THE PARKING CHKLIST, THERE WAS A LOUD BANGING ON THE NOSE. THE AGENT WAS SIGNALLING THE EXTERNAL PWR WAS NOW AVAILABLE. I CHKED THE VOLTS/FREQ AND AFTER BEGINNING THE COOLING PROCESS ON THE APU I SELECTED THE EXTERNAL PWR SUPPLY. THERE WAS A MOMENTARY HESISTANCY FOR THE L BUSS TO ACCEPT PWR. I OBSERVED THAT BOTH THE L AND R BUSSES APPEARED POWERED. I THEN ATTEMPTED TO RECONFIRM THAT THE CHOCKS WERE IN. UNABLE TO ATTRACT AN AGENT'S ATTN I LEFT THE BRAKES SET AND CALLED FOR THE PARKING CHKLIST. WE WERE ON A TIGHT SCHEDULE AND ALREADY BEHIND DUE TO THE PROBS IN CLE. I DESIRED TO RETRIEVE THE FLT RELEASES ASAP AND AFTER THE LAST OF THE PAX DEPLANED I LEFT THE ACFT. THE FO FILLED OUT THE TIMES AND FUEL LOG. I LEFT THE JETWAY VIA THE EXTERIOR STAIRS, PROCEEDED TO OPS AND IMMEDIATELY RETURNED WHEN MY PREFLT DUTIES WERE COMPLETED. UPON MY RETURN I WAS ADVISED THAT I NEEDED TO GO TO THE TICKET PODIUM TO TALK TO 'THEM' ABOUT THE ENG RUNNING? I ASSUMED IT HAD SOMETHING TO DO WITH THE REVERSER UNLOCKED PROBS WE HAD EXPERIENCED. I DIDN'T FIND ANYONE IN PARTICULAR SO I RETURNED TO THE COCKPIT. I BEGAN PREFLT DUTIES AND A FEW MINS LATER THE MAINT SUPVR ARRIVED. HE SAT DOWN AND ASKED ME WHY I HAD LEFT THE ACFT WITH AN ENG RUNNING? I WAS FLABBERGASTED. I ASKED WHAT HE MEANT AND HE EXPLAINED TO ME THAT THE LINE MECH HAD SHUT DOWN THE R ENG. I WAS COMPLETELY DUMBFOUNDED. HOW COULD I HAVE COMMITTED SUCH EGREGIOUS TRANSGRESSION. I SPOKE WITH THE MAINT STAFF AND ASSURED THEM I WAS FULLY AWARE OF THE POTENTIAL FOR DISASTER. I CAN ONLY SURMISE THAT MY ATTN WAS SO DISTRACTED BY THE ONGOING EVENTS THAT THE R ENG WAS NOT SHUT DOWN ON TAXI IN. THE MECH WAS NOT SURE IF THE FUEL CTL WAS IN THE FULL ON POS OR PARTIALLY OFF. MY NORMAL CHKLIST ROUTINE WAS INTERRUPTED SEVERAL TIMES PARTICULARLY BY THE ATTEMPTS TO RECONFIRM THE CHOCKS WERE IN. I HAVE IN THE PAST EXPERIENCED ERRONEOUS CHOCK INDICATIONS. SO AT BUSY CONGESTED AREAS I OFTEN DOUBLE CHK THE CHOCKS. AS I WAS UNABLE TO RECONFIRM THE CHOCKS I LEFT THE BRAKES SET. HOWEVER I STILL DO NOT UNDERSTAND HOW I COULD HAVE PERCEIVED THE APU OR THE EXTERNAL ELECTRICAL PWR SYS POWERING THE R AC BUSS. THE R ENG GENERATOR SHOULD HAVE MAINTAINED PRIORITY. I DID NOT OBSERVE ANYTHING OUT OF THE ORDINARY IN REGARDS TO THE ELECTRICAL SYS OP.

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.