Accident Sequence
During the landing roll, the tailwheel airplane veered off the runway and struck a muddy ditch. The pilot reported that after touchdown the airplane turned left and he applied right rudder to try to realign with the runway centerline. He stated that "next we were heading extreme right, I had a feeling the tailwheel was off the ground."
The flight instructor reported that she was "talking [the pilot] through the landing, and also helping out with [control] stick movement." She stated that after touchdown, as she began to pull the control stick aft, the pilot pushed the stick forward, which raised the tailwheel off the runway. The instructor also said that the pilot "pushed right rudder," which caused the airplane to turn "sideways."
The flight instructor indicated that she "immediately brought the [control] stick back and tried to correct the rudder." She reported that the tailwheel came back down onto the runway, but she could not "correct the rudder" because of "resistance." The instructor stated that she believed the pilot had "frozen on the controls." As a result, she "slam[med] on the brakes" in an effort to stop before the airplane entered a ditch along the runway. She noted that the "mud was so deep that the brakes were not effective and [airplane] kept sliding" into the ditch, where it nosed over.
Pilot and Instructor Experience
The pilot had no prior experience in the accident airplane make/model before this flight. The flight instructor had approximately 20 hours of experience in conventional (tailwheel) airplanes, of which 16.6 hours were in the accident airplane make/model.