What happened
On December 8, 2019, a Grumman G-164-B, registration CX-OTA-R, was conducting agricultural spraying operations over a rice crop near Rio Branco, Cerro Largo. The mission involved applying urea fertilizer using a temporary landing strip consisting of dry, highly compacted earth, measuring approximately 780 meters in length and 10 meters in width.
After completing several successful sorties during the morning, the aircraft performed its tenth flight of the afternoon session. Following the discharge of fertilizer, the pilot landed on the temporary runway in an ESE to WNW direction with a headwind. As the aircraft was taxiing toward the ground support station located near the WNW end of the strip, it suddenly veered to the left. The aircraft exited the boundaries of the runway and came to a stop approximately 1.5 meters from a drainage ditch, resting at a heading of 280° with a 40° nose-down attitude.
The pilot was uninjured and successfully executed emergency shutdown procedures before evacuating the aircraft. There was no fire, and the aircraft sustained minor damage.
The investigation
The CIAIA investigation included an inspection of the site and the aircraft's physical condition. Investigators examined the landing gear, the right landing gear strut, the propeller, the engine, and the lower leading edge of the right wing. The investigation confirmed that all aircraft and pilot documentation was current and valid. The inspection of the runway surface revealed that the lack of recent rainfall had resulted in an extremely hard, smooth, and compacted surface.
Findings
- The primary cause of the excursion was the failure of the left main landing gear tire during the landing roll.
- This failure caused the aircraft to deviate unexpectedly to the left.
- The subsequent impact with a mound of earth caused the right landing gear strut to fracture.
- The aircraft sustained damage to the lower leading edge of the right wing.
- The propeller and engine remained functional and undamaged despite the impact.