Accident Narrative
A flight instructor, serving as a safety pilot for a tailwheel-equipped airplane, reported that he opted to take off from a grass runway instead of a concrete runway in order to expedite the departure. During the soft-field takeoff roll, approximately midway, he observed that the airplane was "struggling to build airspeed." The runway had previously thawed and was described as "wet spongy sod." The instructor reduced power and applied the brakes to abort the takeoff, but the airplane overran the end of the runway, collided with a snow bank, and subsequently nosed over.
Damage
The airplane sustained substantial damage to the fuselage as a result of the accident.
Findings
The flight instructor reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.