What happened
On April 26, 2009, an EMB 711ST, registration PT-RLR, was performing a flight from Cuiabá to the Vila Bela da Santíssima Trindade aerodrome in Mato Grosso, Brazil. During the landing phase on runway 19, the aircraft touched down on irregular terrain approximately 100 meters before the actual start of the grass runway.
Upon contact with the uneven ground, the pilot lost control of the aircraft during the landing roll. The aircraft veered to the left, eventually coming to a stop about 10 meters outside the left edge of the runway. The impact and subsequent excursion caused heavy damage to the nose gear, the right landing gear, the right wing, the aileron, and the flap. Both the pilot and the passenger escaped the accident uninjured.
The investigation
CENIPA investigators examined the site and the operational conditions of the aerodrome. The investigation established that the pilot was a commercial pilot with a valid medical certificate and appropriate ratings, though he was still familiarizing himself with this specific aircraft model and had never previously landed at this location.
The investigation focused on the visual characteristics of the airfield. It was determined that the grass on the runway surface was nearly indistinguishable from the surrounding vegetation when viewed from the air. Recent heavy rains in the region had caused rapid vegetation growth, which obscured the visual boundaries of the runway threshold.
Findings
- The pilot performed the touchdown before the runway threshold due to an optical illusion caused by the lack of visual contrast between the runway and the surrounding environment.
- The similarity between the runway grass and the adjacent vegetation made it difficult to identify the runway limits from the air.
- The aircraft was in a valid state of airworthiness with all maintenance records up to date.
- The pilot had no prior landing experience at this specific aerodrome.