Narrative:

Shortly after completing the parking checklist the ground personnel via the headset informed us that the left engine was still running. This puzzled us as we had verified 'fuel flow zero' on the parking checklist. Closer examination indicated that the left engine was still turning albeit at a reduced RPM. My initial first reaction was that the fuel cutoff valve had failed to completely close. I had experienced this before. My next step was to pull the engine fire extinguisher handle which did not alleviate the situation. The ground person speaking to me through the headset was attempting to give me instructions which I could not initially understand. I finally understood that he wanted me to turn off the APU (auxiliary power unit) bleed valve which I did. By accomplishing this the left engine did spool down to 0 RPM. At this point I began to perceive that the engine was not actually running but rather was being driven by its respective starter for a then unknown reason. At some point I perceived that the ground person I was speaking with on the headset was our mechanic. When the mechanic came to the flight deck he discovered that the left engine start switch was about halfway into the ground position. It is my belief that the left engine starter engaged and began turning the engine after it was shut down. Closing the APU bleed air switch removed the air necessary to drive the starter.I cannot offer an explanation how the left engine start switch ended up in the 'half' ground position. During flight we had no indications from the overhead panel or the EICAS system that anything was amiss. It is my belief that no limitations were exceeded as this event lasted a very short time.

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Original NASA ASRS Text

Title: B767 flight crew reported inadvertently engaging the air start on the left engine; causing the engine to continue turning after shutdown.

Narrative: Shortly after completing the Parking Checklist the ground personnel via the headset informed us that the left engine was still running. This puzzled us as we had verified 'fuel flow zero' on the Parking Checklist. Closer examination indicated that the left engine was still turning albeit at a reduced RPM. My initial first reaction was that the fuel cutoff valve had failed to completely close. I had experienced this before. My next step was to pull the engine fire extinguisher handle which did not alleviate the situation. The ground person speaking to me through the headset was attempting to give me instructions which I could not initially understand. I finally understood that he wanted me to turn off the APU (Auxiliary Power Unit) Bleed valve which I did. By accomplishing this the Left Engine did spool down to 0 RPM. At this point I began to perceive that the engine was not actually running but rather was being driven by its respective starter for a then unknown reason. At some point I perceived that the ground person I was speaking with on the headset was our mechanic. When the mechanic came to the flight deck he discovered that the left engine start switch was about halfway into the ground position. It is my belief that the left engine starter engaged and began turning the engine after it was shut down. Closing the APU bleed air switch removed the air necessary to drive the starter.I cannot offer an explanation how the left engine start switch ended up in the 'half' ground position. During flight we had no indications from the overhead panel or the EICAS system that anything was amiss. It is my belief that NO limitations were exceeded as this event lasted a very short time.

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.