What happened
On February 5, 2016, an Embraer EMB-202A agricultural aircraft, registration PT-VYJ, was performing pesticide application over sugarcane crops near Indiaporã, São Paulo. During the fourth pass of the operation, the aircraft struck a vulture on the leading edge of the right wing.
Following the impact, the pilot determined the aircraft was still responding normally to flight controls and elected to proceed to an alternative landing site approximately 22 nautical miles away in Mesópolis, São Paulo. However, during the final approach at a low altitude, the right wing experienced a loss of lift. The pilot was unable to recover control before a heavy touchdown, which caused the aircraft to veer to the right and exit the landing area into a plantation. The propeller struck the ground, causing the engine to stop abruptly. The aircraft sustained substantial damage, but the pilot remained uninjured.
The investigation
CENIPA investigators examined the physical damage to the aircraft and the flight sequence. The investigation established that the bird strike caused denting on the right wing's leading edge, which altered the aerodynamic profile and disrupted airflow. This deformation increased the stall speed of the right wing. There was also evidence that the stall warning sensor, located at the impact site, may have been compromised.
Investigators noted that the pilot utilized a landing technique involving low speed and high deceleration, common for short agricultural strips. However, given the altered wing geometry, the investigation found that the pilot's approach speed was insufficient to maintain a safety margin. The investigation also reviewed the pilot's credentials, finding all medical and flight licenses were valid, and the aircraft's maintenance records were up to date.
Findings
- The bird strike caused structural deformation of the right wing's leading edge, altering the aerodynamic profile.
- The impact likely rendered the stall warning system inoperable or unreliable.
- The pilot's decision to use a low-speed landing technique, combined with the increased stall speed caused by the wing damage, led to an uncommanded stall during the final approach.
- The pilot did not adopt a more conservative approach speed that could have compensated for the damaged aerodynamic surface.