Narrative:

We deplaned as normal and I ran the shutdown checklist minus the packs; APU; and battery master. The bags were taking a long time to arrive so I stepped out to see what was happening. At the same time I grabbed my flight case and set it outside the plane. There was only one ramper unloading all of our bags and passengers were asking me questions. I went back on to the plane to get mine and the first officer's carry-on bag and came back to the jet bridge. At this point all four crew members were standing there with the passengers because there wasn't a gate agent on the jet bridge. One of our flight attendants was saying 'let's go' and they were waiting on me as I was dealing with passengers and waiting for the gate agent to take over on the jet bridge. Once the gate agent walked down and said she had it and 'goodnight' we began walking up the jet bridge and off to our hotel van.once on the hotel van and we started driving I was thinking back about our post flight and became uncertain I had finished the checklist and shut down the APU. I ran up and asked the driver to let me back off the shuttle and told the crew I would meet them at the hotel. I ran to security and tsa was closed for letting departing crew/pax through. I spoke with two police officers and asked if they could find an escort for me. If not I intended to call mx and ask for their assistance. The officer left to find me a [company] supervisor. After about 25 minutes a flight crew appeared and said they had run our checklist slowly but surely and secured the APU and the cockpit was cold and dark. I was unable to find out who they worked for but was grateful that they helped. However I would have not allowed them on board our aircraft because they do not work for us.I believe this occurred due to distraction from the passengers when I was on the jet bridge and the loud jet bridge air. Neither the first officer nor I noticed the APU running in latter conversation. In addition the 'want' to get to our hotel since we were down to about 12 hours rest from the crew. And not running the checklist as a whole once passengers had fully deplaned. I realized my error and after thousands of flights this is a first. I tried to correct it as soon as possible but could not; due to security being closed. And lastly; had I known the officer was going to allow another crew on to our aircraft I would have refused it and contacted mx or the chief pilot for guidance.

Google
 

Original NASA ASRS Text

Title: A CRJ-900 Captain; distracted after deplaning; forgot to finish the shutdown checklist and left the APU running. The Captain remembered and returned to the airport only to discover another carrier's flight crew secured the aircraft.

Narrative: We deplaned as normal and I ran the shutdown checklist minus the Packs; APU; and Battery Master. The bags were taking a long time to arrive so I stepped out to see what was happening. At the same time I grabbed my flight case and set it outside the plane. There was only one ramper unloading all of our bags and passengers were asking me questions. I went back on to the plane to get mine and the FO's carry-on bag and came back to the jet bridge. At this point all four Crew Members were standing there with the passengers because there wasn't a gate agent on the jet bridge. One of our Flight Attendants was saying 'let's go' and they were waiting on me as I was dealing with passengers and waiting for the gate agent to take over on the jet bridge. Once the gate agent walked down and said she had it and 'goodnight' we began walking up the jet bridge and off to our hotel van.Once on the hotel van and we started driving I was thinking back about our post flight and became uncertain I had finished the checklist and shut down the APU. I ran up and asked the driver to let me back off the shuttle and told the crew I would meet them at the hotel. I ran to security and TSA was closed for letting departing crew/pax through. I spoke with two Police Officers and asked if they could find an escort for me. If not I intended to call MX and ask for their assistance. The officer left to find me a [Company] Supervisor. After about 25 minutes a flight crew appeared and said they had run our checklist slowly but surely and secured the APU and the cockpit was cold and dark. I was unable to find out who they worked for but was grateful that they helped. However I would have not allowed them on board our aircraft because they do not work for us.I believe this occurred due to distraction from the passengers when I was on the jet bridge and the loud jet bridge air. Neither the FO nor I noticed the APU running in latter conversation. In addition the 'want' to get to our hotel since we were down to about 12 hours rest from the crew. And not running the checklist as a whole once passengers had fully deplaned. I realized my error and after thousands of flights this is a first. I tried to correct it ASAP but could not; due to security being closed. And lastly; had I known the officer was going to allow another crew on to our aircraft I would have refused it and contacted MX or the Chief Pilot for guidance.

Data retrieved from NASA's ASRS site 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.