What happened
On a morning in British Columbia, a Seair Cessna 208 Caravan departed Abbotsford Airport on a private flight bound for the Bahamas. Shortly after takeoff, while climbing through approximately 400 feet, the pilot began retracting the flaps from 10 to zero degrees. During this maneuver, the aircraft suddenly became uncontrollable, banking sharply to the left and descending rapidly. The aircraft struck a field about half a mile south of the runway threshold, resulting in the destruction of the plane. The pilot sustained serious injuries, two passengers were seriously injured, and three others suffered minor injuries.
The investigation
The investigation examined the aircraft's condition, the pilot's experience, and the environmental factors present at the time of the accident. Investigators found that the aircraft was significantly heavier than the pilot had estimated. While the pilot believed the plane was under its maximum takeoff weight, the actual weight was approximately 510 pounds over the limit. This discrepancy was partly due to recent unrecorded interior modifications that increased the empty weight of the aircraft.
Furthermore, the investigation focused on the state of the aircraft's lifting surfaces. Although the pilot noted a thin layer of frost on the wings during his pre-flight inspection, he believed it would melt during the climb. However, witnesses reported a much thicker layer of frost, approximately 1/4 inch, covering the aircraft. The investigation also reviewed the pilot's training, noting that while he was experienced in float-equipped aircraft, his recent training for this specific model focused on wheel configurations rather than the amphibious setup used in this flight.
Findings
- The pilot operated the aircraft with frost adhering to the lifting surfaces, which increased aerodynamic drag and reduced the wings' ability to generate lift.
- The aircraft was overloaded by approximately 510 pounds at takeoff, which negatively impacted performance.
- The aircraft entered an aerodynamic stall and lost control specifically when the flaps were retracted, a move that further reduced lift on the already compromised wings.
- Essential weight and balance documentation and aircraft logs had not been updated to reflect recent interior changes.