What happened
On January 19, 2015, an agricultural flight involving a Neiva EMB-202, registration PT-UNC, was attempting to take off from an improvised grass runway at Fazenda Santa Clara, located in São Borja, Rio Grande do Sul. The aircraft was being operated by Estiva Aviação Agrícola Ltda. for the purpose of applying urea fertilizer.
During the takeoff roll, the aircraft failed to achieve sufficient lift to complete the takeoff and maintain level flight. As the aircraft approached the end of the runway, the pilot released the urea load and extended the flaps to their full position to increase lift. However, the aircraft failed to rotate properly, crossed a small dam, and collided with the terrain, resulting in a nose-down impact. The aircraft sustained substantial damage, though the pilot remained uninjured.
The investigation
The investigation examined the takeoff performance and environmental conditions of the runway. The runway was a grass strip approximately 600 meters long, situated at an altitude of 300 feet, with an irregular upward gradient of approximately 1.5%. At the time of the accident, the aircraft had a total weight of 1,660 kg, including 450 kg of urea. Environmental conditions included an ambient temperature of approximately 27°C and a headwind component of about 3 knots.
Investigators noted that the aircraft's Operating Manual (MO-202) provided performance tables that did not account for specific variables such as grass surfaces, wind, or runway gradient. While the pilot had previously operated on this runway with a heavier load (500 kg of fertilizer), the investigation considered how the specific surface and gradient conditions might have increased the required takeoff distance. Additionally, the investigation looked into the pilot's decision to use full flap extension, noting that the manufacturer's manual did not provide for takeoff configurations other than 8 degrees of flap deflection. The possibility of inadvertent brake application during the roll was also considered as a factor that could have prevented the aircraft from reaching rotation speed.
Findings
- Pilot judgment regarding the takeoff performance and configuration.
- The aircraft's performance tables did not include variables for grass runways, wind, or runway gradient.
- The pilot extended the flaps to the full position during the takeoff roll, a configuration not specified by the manufacturer for takeoff.