What happened
On December 3, 2014, a Piper PA-31 (registration HK-4464), operated by Nacional de Aviación S.A., was performing a non-scheduled passenger flight from Guaymaral to Bahía Solano. The aircraft was carrying two crew members and eight passengers, including five children and three adults.
During the flight, the pilot reported technical issues and instrument temperature fluctuations to Bogotá Information. The pilot initially requested to return to Guaymaral but later requested permission to divert to Mariquita airport due to the ongoing technical difficulties. While attempting to maneuver toward the runway, the aircraft experienced a significant loss of airspeed. In an attempt to maintain terrain separation at low altitude, the aircraft entered a stall and impacted the ground approximately 5 nautical miles from the head of runway 19 at Hacienda El Edén. A post-impact fire occurred, and all 10 fatalities were caused by the forces of impact.
The investigation
The GRIAA investigation examined the aircraft's maintenance history, crew records, and the sequence of flight maneuvers. Investigators reviewed the aircraft's maintenance logs, which noted issues with the right engine a month prior to the accident. The investigation also scrutinized the pilot's training records, noting discrepancies in the required proficiency checks and the lack of standardized procedures between the crew members, who were flying together for the first time. Additionally, the investigation looked into the operational oversight of the operator regarding crew training and contract standardization.
Findings
- The primary cause of the accident was the malfunction of the right engine during cruise flight, which led to a loss of airspeed and subsequent aerodynamic stall.
- The pilot experienced a loss of situational awareness during the turn, resulting in a flight path that drifted away from the intended destination.
- The aircraft was operating with insufficient airspeed and altitude to safely manage the engine failure while attempting to maintain terrain separation.
- Maintenance records indicated that the aircraft had been inoperative for over six months, and some required manufacturer-mandated maintenance tasks had not been completed.
- The crew members were operating as an unstandardized team, having never flown together in this specific aircraft for the operator, and lacked established standard operating procedures (SOPs) for such emergencies.
Safety action
- The investigation recommended that the operator, Nacional de Aviación S.A., standardize employment contracts for flight crews to ensure proper selection and training profiles.
- Recommendations were made for the operator to implement and verify the results of its Safety Management System (SMS) action plans.
- The Civil Aviation Authority (UAEAC) was advised to conduct an audit of the operator's compliance with Colombian Aeronautical Regulations (RAC) and to review its operational permits.