What happened
On 24 April 2007, a Eurocopter EC135 helicopter, registration SE-HPS, was conducting a coordinated training exercise between the Swedish Police Wing and the Gothenburg police picket force at the Sisjön sports area. The exercise was designed to train officers in helicopter transport and embarkation/disembarkation procedures.
During the final phase of the flight, intended as "environment training" to familiarize passengers with tactical maneuvers, the helicopter performed several steep turns and high-G maneuvers. After flying at tree-top level, the aircraft climbed abruptly to approximately 100 meters. During this maneuver, the helicopter appeared to lose speed with a nose-up attitude before pitching to the port side and entering a steep dive.
The aircraft struck the ground at high forward speed, with the tail boom and landing skids impacting first. The helicopter then capsized and rolled multiple times in a water-filled ditch. The impact caused the cabin to disintegrate, and the passengers were ejected from their seats. The pilot sustained fatal injuries due to thoracic compression, while three passengers suffered serious injuries, including vertebral fractures.
The investigation
The Swedish Accident Investigation Authority (SHK) examined the aircraft, the flight history, and the organizational structure of the Swedish Police Wing. The investigation found no technical malfunctions within the helicopter itself. Investigators also reviewed the maintenance of the aircraft, specifically the use of snow skids on the undercarriage, and analyzed the regulatory oversight provided by the Civil Aviation Authority.
Findings
- The flight involved maneuvers that departed from approved procedures and pushed the aircraft close to, or partially beyond, its operational limits.
- The snow skids mounted on the undercarriage may have negatively impacted the helicopter's maneuverability during extreme flight conditions.
- There were significant organizational deficiencies within the Swedish Police Wing, including an unsatisfactory working climate and a lack of effective management oversight.
- The Civil Aviation Authority failed to provide adequate inspection of the police flying activities, having not inspected the unit's operations for nearly four years.
- The accident was triggered by the pilot's specific flight maneuvers in conjunction with the potential aerodynamic effects of the snow skids.
Safety action
- The Civil Aviation Authority is recommended to develop national regulations specifically adapted to the activities of the Swedish Police Wing, aligning them with JAR-OPS 3 requirements.
- The Authority should review its internal routines for granting permits and inspecting commercial flight activities to prevent unauthorized or dangerous flight operations.