What happened
On September 24, 2021, at approximately 11:15 local time, a Piper 32RT-300T, registration HK4773, was performing a takeoff roll on runway 04 at La Primavera Aerodrome (SKIM) in Vichada, Colombia. The aircraft, operating as an unscheduled air taxi service, was carrying one pilot and five passengers.
During the takeoff roll, the pilot attempted to maintain the aircraft on the left side of the runway to avoid significant potholes and surface irregularities located on the right side of the runway extension. As the aircraft reached a speed of between 40 and 50 knots, approximately three-quarters of the way down the runway, the pilot felt a sudden impact on the left side of the aircraft. Following this impact, the pilot lost directional control, and the aircraft veered off the left side of the runway into the safety area. The aircraft traveled approximately 400 meters before coming to a stop. All six occupants successfully evacuated the aircraft without injury, though the aircraft sustained substantial damage to its nose gear, ventral fuselage, and wing structure.
The investigation
The GRIAA investigation focused on the physical state of the aerodrome and the aircraft's configuration during the incident. Investigators examined the runway surface at La Primavera, finding significant deterioration, including potholes, undulations, and loss of asphalt aggregate. The investigation also reviewed the aircraft's weight and balance, noting that the center of gravity was positioned near the rear limit. Additionally, the investigation assessed the pilot's performance and the operator's risk management protocols regarding known airfield deficiencies.
Findings
- The primary cause of the lateral runway excursion was the loss of directional control during the takeoff roll.
- Directional control via the nose wheel steering (NWS) system was lost because the nose gear lifted off the pavement. This lifting was triggered by the aircraft's interaction with the uneven runway surface (potholes and undulations) and was exacerbated by the aircraft's center of gravity being near the rear limit.
- The loss of effectiveness of the rudder due to low airspeed contributed to the inability to correct the deviation.
- Environmental factors, including a wet runway and a crosswind from the right, increased the difficulty of maintaining directional control.
- The operator demonstrated a weakness in risk management by conducting operations at an aerodrome with known, significant pavement deficiencies.
- The runway surface at La Primavera had not undergone a formal inspection by the aeronautical authority since 2015.