What happened
On June 27, 2018, an Ayres S2R-T34, registration HK3446, was performing agricultural spraying operations near the Los Planes airstrip in Apartadó, Antioquia. During the initial climb following takeoff, the aircraft experienced a significant loss of altitude. The pilot attempted an emergency discharge of the chemical payload to regain altitude, but the maneuver was unsuccessful.
The aircraft subsequently struck a utility pole and power lines before impacting an asphalt road and coming to rest in a drainage canal. A post-impact fire broke out in the engine compartment, which was extinguished by bystanders and ground personnel. The pilot sustained minor injuries and was able to evacuate the aircraft on his own.
The investigation
The GRIAA investigation focused on the aircraft's performance during the takeoff roll and the operational procedures of the operator, Calima S.A.S. Investigators analyzed the takeoff speed profile and found that the aircraft reached a speed of 85.4 mph at a point where typical operations averaged 93.8 mph. The investigation also examined the engine, which was found to be in normal operating condition prior to the accident, and reviewed the pilot's training and the company's operational manuals.
Findings
- The primary cause of the accident was a loss of lift and control resulting from an inadequate takeoff technique, specifically a premature rotation at speeds lower than required for safe flight. The aircraft initially achieved flight through ground effect, but was unable to maintain acceleration or climb once it left that effect.
- The operator lacked operational procedures to determine and verify the necessary takeoff speeds.
- There was a lack of established procedures for analyzing runway characteristics and determining declared distances at the aerodromes operated by the company.