Narrative:

Tailwheel training. Upon teaching wheel landings to a student; the stick was not moved forward to kill the lift for landing. Thus; rudder authority was lost and we skidded off the runway into a ditch. I had the controls immediately after we went for the ditch. I added full power to avoid flipping nose over in the ditch. We crossed this ditch and were heading towards another ditch on the opposite side of the taxiway. I decided to not chance a second ditch crossing and tried to keep it on the taxiway. At this point in time; the tailwheel locked and we rotated counterclockwise and the right wing skidded across the ground. The only damage was on the right wing tip next to the aileron.

Google
 

Original NASA ASRS Text

Title: A flight instructor and his student; practicing wheel landings in a PA-18 Super Cub; lost control on landing; performed a ground loop; departed the runway; powered across one ditch; avoided another and came to rest on a taxiway after scraping a wingtip. Minor damage and no injuries resulted.

Narrative: Tailwheel training. Upon teaching wheel landings to a student; the stick was not moved forward to kill the lift for landing. Thus; rudder authority was lost and we skidded off the runway into a ditch. I had the controls immediately after we went for the ditch. I added full power to avoid flipping nose over in the ditch. We crossed this ditch and were heading towards another ditch on the opposite side of the taxiway. I decided to not chance a second ditch crossing and tried to keep it on the taxiway. At this point in time; the tailwheel locked and we rotated counterclockwise and the right wing skidded across the ground. The only damage was on the right wing tip next to the aileron.

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.