What happened
On February 6, 2010, a Cessna A 188B, registration PT-WKN, was performing an agricultural spraying operation near Itumbiara, Goiás. The aircraft departed from a dirt runway (known as Pista Grupo Dias) using runway 20. During the initial climb, the aircraft encountered obstacles ahead, including a row of trees and high-voltage power lines.
In an attempt to clear these obstacles, the pilot executed a sharp left turn while simultaneously jettisoning the hopper load. Despite the reduction in weight, the aircraft's performance was insufficient to maintain flight during the high-bank maneuver. The aircraft lost lift and struck the ground at a low altitude, resulting in a post-impact fire. The pilot sustained fatal injuries.
The investigation
CENIPA investigators determined that the aircraft was operating significantly above its maximum allowable takeoff weight. The hopper had been loaded with approximately 1,400 lbs of product, and the aircraft was carrying 60 lbs of fuel.
Analysis of the flight path showed that the aircraft entered a turn with a bank angle of approximately 66 degrees. At the aircraft's speed of 75 mph, the required lift to sustain such a steep turn exceeded the available performance, especially given the heavy takeoff weight. Investigators also noted that while the engine showed no internal mechanical failure, the fuel injector for cylinder number 3 was found to be loose due to worn threads, suggesting improper installation during previous maintenance.
Findings
- Inadequate flight planning, as the pilot chose a runway heading (20) that presented obstacles, rather than using the alternative runway (02) which was clear of obstructions.
- Excessive takeoff weight, which compromised the aircraft's climb performance and maneuverability.
- Loss of control during a high-angle bank maneuver at low altitude.
- The pilot's attempt to perform an emergency forced landing due to poor performance led to a significant reduction in engine power/noise observed by witnesses.
Safety action
Following the investigation, several safety recommendations were issued:
- To the operator (Aero Agrícola Rio Verde): Pilots must evaluate runway extensions for obstacles and select takeoff headings that provide the best escape routes for forced landings. Additionally, pilots should undergo retraining regarding aircraft operational limits and takeoff weight calculations.
- To the maintenance facility (Conte Aero): Emphasis was placed on the necessity of following technical orders strictly to prevent improper installation of components like fuel injectors.