What happened
On October 18, 2020, a Cessna 172L, registration HK5101G, was conducting solo training maneuvers at Guaymaral Airport in Bogotá. The flight consisted of a series of touch-and-go landings. After completing two successful maneuvers, the aircraft was in a climbing turn during a crosswind leg when it experienced a sudden and significant loss of airspeed.
Believing the aircraft had suffered a loss of engine power, the student pilot requested an immediate return to the runway and attempted to approach runway 29. However, the aircraft could not reach the runway, forcing an emergency landing in a nearby pasture. During the landing roll, the aircraft struck two cattle, causing the death of the animals. The impact caused the nose gear to collapse, and the aircraft subsequently caught fire, destroying approximately 80% of the airframe. The student pilot, who was found partially outside the cockpit, sustained serious injuries and was evacuated by a National Police helicopter.
The investigation
The GRIAA investigation focused on the mechanical configuration of the aircraft and the pilot's decision-making process. Investigators examined the flap control system and found that the switch installed in the aircraft lacked a spring-loaded mechanism to return it to the "off" position. This allowed the switch to remain in the "down" position following an accidental movement.
Furthermore, the investigation analyzed the environmental factors at Guaymaral Airport, noting that the high density altitude of the airfield significantly limited the engine and aerodynamic performance of the aircraft. The investigation also reviewed the flight school's training curriculum, specifically regarding how students are prepared for abnormal configurations and high-altitude performance limitations.
Findings
- The primary cause of the accident was the inadvertent activation of the flap switch to the full flaps position, which increased parasitic drag and prevented the aircraft from maintaining sufficient airspeed for climb and acceleration.
- The flap switch design was a contributing factor, as it lacked a detent or spring-back feature to prevent accidental deployment.
- The student pilot's inexperience contributed to the accident, as they failed to recognize the aerodynamic cause of the speed loss and incorrectly assumed an engine power loss had occurred.
- Deficiencies in the training program were identified, specifically a lack of emphasis on identifying abnormal flight conditions and the impact of high-density altitude on aircraft performance during takeoff and climbs.