What happened
On April 25, 2003, an Eurocopter AS 350 B3, registration LN-ODJ, operated by Pegasus Helicopter AS, crashed near Sekse in Ullensvang, Hordaland. The aircraft was engaged in a specialized agricultural operation involving the spreading of lime over pastures using an underslung container.
The pilot in command was completing training for this specific type of work. Earlier that day, during a reconnaissance flight, the pilot had observed a high-voltage power line crossing the intended flight path. However, during the subsequent transport flight with a second load of lime, the pilot failed to account for this obstacle. While climbing through steep terrain at approximately 31 meters above the ground, the helicopter struck three power lines. The impact caused the aircraft to lose control and enter a rapid rotation around its vertical axis. The helicopter eventually struck a tractor road approximately 80 meters from the initial point of impact. Despite the destruction of the aircraft, the pilot escaped the crash without physical injuries.
The investigation
The Norwegian Safety Investigation Authority (NSIA) examined the flight sequence, the pilot's training status, and the operator's safety procedures. The investigation established that the pilot had flown at an unnecessarily low altitude during the transport phase, with the underslung load passing only about 23 meters above the terrain. The investigation also looked into the company's history, noting that the operator had experienced several other collisions with suspended wires over a relatively short period.
Findings
Several critical factors contributed to the accident:
- Unnecessary risk-taking: The pilot chose to fly at a very low altitude during the transport phase, which significantly increased the risk of terrain and obstacle strikes.
- Failure to identify hazards: Although the power lines were spotted during reconnaissance, the pilot failed to recognize or avoid them during the actual operation. The lines were difficult to see due to their color and were not marked on available charts.
- Inadequate risk management: The operator lacked a structured approach to risk assessment for lime-spreading operations. The company's procedures for identifying and recording obstacles were insufficient.
- Operational deficiencies: The company's procedures for planning and reconnaissance were too general and lacked specific instructions for managing hazards like power lines.
Safety action
The NSIA issued several safety recommendations to address the systemic issues identified:
- The operator should formalize its flight safety work and implement more rigorous risk analyses.
- Procedures for reconnaissance and the mapping of aerial obstacles must be revised and made more robust.
- The company must ensure all cabin equipment, such as fire extinguishers, is properly secured to prevent them from becoming projectiles during an impact.
- The Civil Aviation Authority should evaluate the durability of certain emergency locator transmitter (ELT) antennas used on Norwegian aircraft.