Narrative:

After landing; the pilot flying taxied off the runway and proceeded to taxi straight down to the departure end of the runway. Out of nowhere; the airplane suddenly started to turn to the right. The student commented to me that 'I can't straighten out the nose.' I said 'I have the controls.' the student released the controls and I tried to get the airplane back on the taxiway center line; but at this point the right rudder was deflected full right. The airplane was on the grass. Then; I felt the nose dip down and collapse. The prop struck the ground and that's when we shut down both engines before any further damage. We then proceeded to secure and exit the airplane.

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Original NASA ASRS Text

Title: C402B instructor and student pilot reported a loss of directional control during taxi that resulted in nose gear collapse and a prop strike.

Narrative: After landing; the pilot flying taxied off the runway and proceeded to taxi straight down to the departure end of the runway. Out of nowhere; the airplane suddenly started to turn to the right. The student commented to me that 'I can't straighten out the nose.' I said 'I have the controls.' The student released the controls and I tried to get the airplane back on the taxiway center line; but at this point the right rudder was deflected full right. The airplane was on the grass. Then; I felt the nose dip down and collapse. The prop struck the ground and that's when we shut down both engines before any further damage. We then proceeded to secure and exit the airplane.

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.