What happened
On October 6, 2014, at approximately 12:31 UTC, a Cessna A188B, registration HK1746, was conducting aerial spraying operations over sugarcane crops in the municipality of Rozo, Valle del Cauca. The aircraft had departed from the "Las Cañas" airstrip earlier that day under visual meteorological conditions to discharge pesticides over the Tumaco Ingenio fields.
While the pilot was adjusting the throttle to return to base, the engine experienced an abrupt vibration and a total loss of power. The engine compartment began emitting smoke, and oil spray from the engine obscured the pilot's forward visibility through the windscreen. The pilot declared an emergency with the Alfonso Bonilla Aragón Tower and performed a forced landing in an unprepared sugarcane field at the Guajira 5 farm. The pilot, who was the sole occupant, exited the aircraft unharmed. The impact caused extensive damage to the airframe, including the separation of the engine and nacelle from the engine mount, failure of the left main landing gear, and damage to the wings and tail section.
The investigation
The GRIAA investigation focused on the mechanical failure of the propulsion system. Investigators examined the propeller, which had sustained a significant fracture, with approximately one-third of one blade missing. The investigation also reviewed the maintenance history of the aircraft and the oversight provided by the operator, ARFA S.A.S.
Evidence was found regarding discrepancies in maintenance documentation, specifically regarding the total hours and inspection dates recorded in the aircraft's annual inspection forms. Furthermore, the investigation scrutinized the quality control processes of the maintenance workshops used by the operator, particularly regarding the repair of propeller components.