What happened
The aircraft collided with the runway at its midpoint while in a thirty-degree nose-low attitude during the initial climb phase. The flight crew initiated the takeoff roll from the northern end of a five-thousand-foot runway. After traveling approximately five hundred feet, the aircraft lifted off normally. To accelerate toward the best climb speed, the pilot relaxed back pressure on the elevator controls.
As the aircraft reached the midpoint of the runway, it began to pitch down gently. The pilot applied nose-up trim, but the descent continued. The pilot observed that the control stick would not move further aft than its neutral position. The aircraft continued to pitch downward until it impacted the runway surface.
The investigation
A post-accident inspection of the airframe revealed an unusual amount of tools and plywood stored in the tail section. Investigators found no items lodged in a manner that would physically interfere with flight controls. All flight control systems demonstrated continuity, but the elevator cables exhibited an unusual amount of slack. While this slack was significant, it was not sufficient to render the aircraft completely uncontrollable under normal circumstances.
Findings
The primary factor contributing to the accident was the shift of loose cargo in the tail section during rotation. This movement altered the center of gravity and increased elevator cable slack, preventing the pilot from maintaining or increasing pitch attitude. The inability to raise the nose resulted in a premature stall and collision with the runway.
Safety message
Proper weight and balance management is critical during takeoff. Loose items in the tail section can shift during rotation, altering control effectiveness and potentially leading to loss of pitch control.