What happened
The certified flight instructor (CFI) was conducting a training exercise on a grass airstrip, demonstrating a simulated short field takeoff procedure to a student pilot. During the initial phase of the maneuver, the student pilot reported that the aircraft appeared to be performing normally while accelerating down the runway.
However, immediately after lift-off, the student pilot found himself unable to gain altitude and climb out of ground effect. Unable to clear the obstacle at the end of the available runway, the aircraft collided with a fence located at the terminus of the runway.
The investigation
Following the accident, investigators examined the aircraft's weight and balance documentation. The analysis revealed that the aircraft was loaded beyond its certified limits at the time of the incident.
Findings
The examination determined that the aircraft was 29 lbs over gross weight when the takeoff roll began. This excess weight likely contributed significantly to the inability to climb out of ground effect, preventing the pilot from clearing the fence at the end of the runway.