What happened
On July 28, 2017, a Cessna 172 N departed from the Allstedt airfield for a private sightseeing flight. The aircraft was carrying the pilot and three passengers. Shortly before departure, the decision was made to add a third passenger to the flight, a change that was not reflected in a revised weight and balance calculation.
During the takeoff roll on runway 25, the aircraft lifted off approximately 50 meters before the halfway mark. However, the aircraft failed to gain sufficient altitude. After passing a photovoltaic installation at the end of the runway, the pilot attempted to maneuver the aircraft, but the plane was unable to clear a nearby treeline. The aircraft subsequently struck trees and collided with the ground. The impact resulted in three serious and one minor injury among the occupants, and the aircraft sustained heavy damage.
The investigation
The BFU investigation focused on the aircraft's performance and the loading conditions at the time of departure. Investigators determined that the aircraft's takeoff mass was approximately 1,230 kg, which exceeded the maximum allowable takeoff mass of 1,043 kg. Furthermore, the center of gravity was found to be outside the permissible range, specifically positioned too far aft.
The investigation also examined the pilot's recent experience, noting that while the pilot was highly experienced in gliders and motor gliders, the last flight in this specific Cessna 172 N had occurred ten months prior. Additionally, the pilot noted that the front passenger might have unintentionally applied the toe brakes during the takeoff roll because the seat was pushed fully forward.
Findings
- The aircraft was operated outside of its permissible weight and center of gravity limits.
- The decision to add an additional passenger at the last minute significantly increased the takeoff weight without a corresponding recalculation of the aircraft's performance capabilities.
- The heavy loading and aft center of gravity prevented the aircraft from developing sufficient airspeed to transition into a steady climb.
- The pilot's lack of recent currency in this specific aircraft type may have contributed to suboptimal control inputs during the critical phase of flight.