Flight Crew Air Transport Pilot (ATP)
Other / Unknown; Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown
Flight Crew Became Reoriented
Human Factors
Landed on runway 28 and taxied toward gate. A few minutes later after getting ENGINE COOL alert and before crossing the runway 27 left; for some strange reason I thought I shut down the right engine. Then taxied only on left engine to the gate since in my mind the right engine was shut down. Parked at the gate and after getting the EXT PWE AVAIL alert I shut down the left engine. My First Officer had to use the restroom so I told her she can go to restroom after turning the seat belt sign off. Then I started to do the parking checklist. I left to get some food and when I returned I was told that right engine was running for few minutes and ramp people told my First Officer and she shut it down. I had a meeting with [the Chief Pilots] and I told them what exactly happened. Up until now some how I still think I shut the engine down few minutes after landing. I honestly don't know what happened and I really can't associate it with any factor. I wasn't over loaded or fatigued. Just an honest mistake. My mind played a game with me since I really; really thought I shut the engine down.
After taxi in; I mentioned to the captain that I needed to use the restroom. Once he received the External Power Available alert; he told me to go ahead and he would complete my checklist. I left the aircraft and could hear him reading the checklist as I departed. I went to the restroom then proceeded to get lunch which I brought back to the aircraft. When I returned to the gate; the ground personnel were gathered around the counter with the gate agent. They said that they could not load or fuel the aircraft because the right engine was still running. I got in the cockpit and shut down the engine. The captain returned from getting himself lunch just a minute or two after me; and I told him what happened. He called the chief pilot and also spoke to the head of maintenance. In the future; I will wait to use the restroom until the checklist is complete.
B717 fight crew reports forgetting to shut down the right engine after gate arrival then departing separately to obtain lunch. The First Officer returns first and is informed the right engine is still running; which is shut down.