What happened
On 20 June 2021, a Beech 36 (Bonanza), registration ZS-NFI, attempted to depart from the Lombard Pan Airstrip in the Northern Cape for a private flight. The aircraft, carrying a pilot and four passengers, was operating under visual flight rules. Prior to departure, the pilot had calculated the aircraft's all-up weight to be 3835lb, well within the 4000lb maximum takeoff weight. The pilot selected a 120° takeoff heading, estimating that 550 metres of runway would be sufficient for the maneuver.
During the takeoff roll, the pilot noted that the aircraft was not accelerating at the expected rate, though it did reach a speed of 70 knots. Upon rotation, the aircraft failed to achieve an adequate climb rate. While maintaining an altitude between 30ft and 50ft, the aircraft began to lose lift. In an attempt to prevent a stall, the pilot attempted to return to the pan; however, the aircraft ran out of runway length. The aircraft struck a tree and underwent a 180-degree ground loop before coming to a halt. The aircraft sustained substantial damage, but there were 0 fatalities and 0 injuries among the occupants.
The investigation
The investigation examined the flight planning, weight and balance calculations, and the physical conditions of the takeoff site. The inquiry reviewed the pilot's pre-flight assessments, including the estimated runway requirements and the aircraft's center of gravity (CoG) configuration. The investigation also looked into the surface conditions of the Lombard Pan Airstrip and the aircraft's performance during the initial takeoff phase.
Findings
- The primary cause of the failure to climb was that the center of gravity was positioned too close to the aft limit.
- The pilot failed to account for the increased rolling resistance provided by the gravel surface of the pan during the takeoff roll.
- The aircraft's left wing made contact with a tree during the excursion.