What happened
On March 11, 2018, an Air Tractor AT-502B, registration PR-XEU, was performing an agricultural application flight from a landing strip at Fazenda Água do Índio in Cianorte, Paraná. The flight was operating under visual meteorological conditions.
During the takeoff roll, after rotation, the aircraft experienced a sudden loss of altitude. The pilot reported that the loss of height may have been caused by a downdisturbance or a sudden change in wind direction. In an attempt to recover, the pilot jettisoned the aircraft's load. Despite this action, the aircraft struck vegetation covering an embankment at the end of the runway, sliding approximately 30 meters. The pilot was uninjured, but the aircraft sustained substantial damage.
The investigation
CENIPA investigators analyzed the aircraft's weight and performance capabilities relative to the runway conditions. The investigation established that the aircraft was operating significantly above its maximum allowable takeoff weight. The total takeoff weight was calculated at 4,008 kg, which exceeded the manufacturer's maximum limit of 3,629 kg by 379 kg.
Furthermore, the investigation determined that the available runway length of 750 meters was insufficient for the required takeoff distance. Based on the reported temperature of 28°C and the aircraft's performance charts, a distance of 940 meters would have been required to clear a 50ft obstacle at the end of the runway, even if the aircraft had been within weight limits.
Findings
- The aircraft was operating above the maximum takeoff weight limit.
- Inadequate flight planning contributed to the weight transgression.
- Failures in managerial supervision allowed the aircraft to be loaded beyond its structural and performance limits.
- The runway length was insufficient to accommodate the required takeoff distance under the prevailing environmental conditions.