What happened
On April 20, 2023, a Piper PA 28-180, registration HK1577G, departed from Guaymaral Aerodrome (SKGY) for a visual flight rules (VFR) training mission. The aircraft was occupied by an instructor pilot and a student pilot.
During the initial climb phase, after reaching approximately 400 feet, the crew noticed a progressive loss of engine power. The instructor took control of the aircraft and attempted to recover power by adjusting the fuel mixture to the full rich position and activating the electric fuel pump. Despite these efforts, the engine power continued to fluctuate significantly.
As the aircraft began to lose altitude and the stall warning activated, the instructor determined that returning to the runway was not possible. The instructor declared an emergency with Air Traffic Control and executed an emergency landing in an unprepared field near Chía, Cundinariumca. During the maneuver, the aircraft struck a wire fence, which caused substantial structural damage to the wings and landing gear before the aircraft came to a stop on sloped terrain. Both occupants sustained minor injuries.
The investigation
The GRIAA investigation focused on the engine's performance and the crew's emergency response. Investigators examined the aircraft's maintenance records, which showed the plane was airworthy and compliant with all maintenance programs. The engine, a Lycoming O-360-A4A, showed no apparent mechanical damage or internal failure during post-accident inspection.
Physical evidence at the scene showed the right wing suffered deformation from hitting a fence post, and the left wing was heavily damaged by both the fence impact and contact with the ground. The nose landing gear collapsed upon impact. The investigation also reviewed the crew's use of emergency checklists and the flight school's training standardization regarding engine mixture regulation.
Findings
- The primary cause of the accident was the collision with a wire fence during an emergency landing following a loss of engine power.
- The engine power loss was likely caused by an inappropriate air-fuel mixture regulation, which led to improper combustion.
- The crew failed to follow the manufacturer's established emergency checklists during the critical moments of the power loss.
- A contributing factor was a lack of standardization within the flight training center regarding proper mixture selection for different operating conditions and techniques for identifying engine malfunctions.