What happened
On June 10, 2017, an Emerald Pacific Airlines BELL206B3 helicopter, registration B-31118, crashed in Hualien County, Taiwan, during an aerial filming mission. The aircraft departed from Temple Fah-Lin in Chishang Township at approximately 10:45 hrs. The flight crew consisted of one pilot and two aerial photographers.
At approximately 11:54 hrs, the helicopter impacted the ground at Ranch Sie-Jin. The impact was followed by a severe post-crash fire that destroyed the majority of the fuselage. All 3 fatalities occurred as a result of the accident. While the engine appeared to be operational prior to impact, the intense fire prevented a detailed examination of the powerplant and flight control systems.
The investigation
The investigation was conducted by the Taiwan Transportation Safety Board (formerly ASC) through a combination of site surveys, wreckage examination, interviews, and analysis of maintenance records and onboard video. Because the aircraft was not equipped with a flight recorder, investigators relied on numerical simulations of wind conditions and analysis of the aircraft's warning light filaments to reconstruct the final moments of the flight.
Investigators also examined the pilot's medical status, specifically the presence of antihistamines in the bloodstream, and reviewed the operator's flight duty period (FDP) recording systems and training manuals.
Findings
Several contributing factors and safety risks were identified during the investigation:
- Pilot impairment: The pilot had a significant concentration of the antihistamine Chlorpheniramine in his blood. While the dosage was within normal medicinal limits, the concentration was high enough to potentially cause drowsiness or reduced physical performance.
- Operational fatigue: The pilot was subject to several stressors, including high flight time, long durations of vibration, high cockpit temperatures, and low-altitude mountainous operations, which may have contributed to fatigue.
- Inadequate Crew Resource Management (CRM): The pilot failed to fully communicate or evaluate changes to the flight plan, increasing operational risk during environmental changes.
- Regulatory and management failures: Emerald Pacific Airlines' records for flight duty periods deviated from actual duty time, and the company's systems failed to accurately track compliance with rest period regulations. Additionally, the company's training manual lacked clear procedures for mission aborts and aerial survey risks.
- Safety non-compliance: The investigation noted several instances of the operator deviating from safety protocols, including the use of electronic devices in flight and improper refueling procedures.
Safety action
The investigation led to numerous safety recommendations for both the airline and the Civil Aeronautics Administration (CAA). Key recommendations include establishing clear guidelines for pilot medication usage, enhancing risk assessment procedures for mountainous terrain, and improving the accuracy of flight duty period recording and archiving to ensure compliance with regulatory rest requirements.