Sequence of Events
The certified flight instructor (CFI) was demonstrating a soft field takeoff. After lift-off, the airplane settled back to the runway. It then became airborne again, but control was lost, and the airplane settled into terrain adjacent to the runway.
Wreckage Examination
No discrepancies were found during the examination of the wreckage. The left flap was found deployed to about 10 degrees due to impact damage, and the follow-up cable was slack. The remainder of the flap system was intact. This condition is consistent with the flaps being in the up position at the time of impact.
Flap System Analysis
The flaps are electrically driven through a jack screw to the right flap. The left flap is driven by a follow-up cable through the right flap jack screw; therefore, the left flap cannot be driven to a position to which the right flap is not driven. The right flap was found in the up position.
Relevant Handbook Information
The recommended flap setting for a short field takeoff is 10 degrees. According to the FAA Flight Training Handbook, during a soft field takeoff, the airplane can become airborne at an airspeed below safe climb speed due to the action of ground effect.