Narrative:

While [we were] taxiing for takeoff the captain taxied off of the taxiway. [The event occurred at] an uncontrolled field; and on this particular day an event was being held which resulted in increased air and ground traffic. Both the captain and I were monitoring our respective sides of the aircraft for traffic as we were approaching an active runway. I felt a drag on the aircraft; at which point I told the captain to stop; as I believed that left main gear was in the grass. He said it was not; and then added power; which resulted in the aircraft sinking into the ground. He then shut down the left engine; got out of his seat; walked to the door; looked out; and verified that we were; in fact; stuck. He then returned to the cockpit; shut the aircraft down; and made the appropriate calls.

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Original NASA ASRS Text

Title: A DC9-30; departing a busy uncontrolled airport during a 'fly in' event; inadvertently exited the paved taxiway while attempting a turn to back taxi down a runway for takeoff and got bogged down in the rain softened grass. The aircraft had to be unloaded before it could be returned to the hard surface.

Narrative: While [we were] taxiing for takeoff the Captain taxied off of the taxiway. [The event occurred at] an uncontrolled field; and on this particular day an event was being held which resulted in increased air and ground traffic. Both the Captain and I were monitoring our respective sides of the aircraft for traffic as we were approaching an active runway. I felt a drag on the aircraft; at which point I told the Captain to stop; as I believed that left main gear was in the grass. He said it was not; and then added power; which resulted in the aircraft sinking into the ground. He then shut down the left engine; got out of his seat; walked to the door; looked out; and verified that we were; in fact; stuck. He then returned to the cockpit; shut the aircraft down; and made the appropriate calls.

Data retrieved from NASA's ASRS site as of July 2013 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.