What happened
On January 8, 2022, an Air Tractor AT301, registration HK-4615, was conducting its sixth agricultural spraying flight of the day. The aircraft departed from the Los Almendros airstrip in Carepa, Antioquia, heading toward a banana plantation. Approximately one minute after takeoff, while performing a right-hand turn, the pilot experienced intense vibrations and observed white smoke emanating from the engine. Simultaneously, the engine lost significant power, causing the aircraft to lose both airspeed and altitude.
As the pilot attempted to manage the emergency, the engine eventually failed completely. To avoid a nearby banana packing facility, the pilot maneuvered toward a suitable landing site in a banana field. Because a medium-voltage power line blocked the direct path, the pilot opted to fly underneath the wires, which were positioned at a height of 14 meters. During the landing sequence, the aircraft's right wingtip struck the ground, causing a sharp veer to the right. The nose of the aircraft then struck a steel cable used for harvesting, which resulted in the engine detaching from the fuselage. The aircraft slid through the plantation, sustaining substantial damage. The pilot sustained minor injuries and evacuated the aircraft successfully.
The investigation
The GRIAA investigation focused on the mechanical failure of the Pratt and Whitney radial engine. Investigators performed a detailed fracture analysis of the connecting rod, including metallographic and atomic mapping to examine the material's condition. The examination revealed that a crack had developed in the lower part of the connecting rod. The investigation also reviewed the operator's maintenance records, flight procedures, and the thermal management of the engine during start-up and shut-down cycles.