What happened
On the night of 18 September 2004, a Sikorsky S-76C helicopter, registration SE-JUJ, was performing a Helicopter Emergency Medical Services (HEMS) mission near Skräckskär, Sweden. The crew was tasked with transporting a patient with an acute heart condition from the island of Häradsskär to a university hospital.
The flight was conducted under Visual Flight Rules (VFR) in darkness. As the aircraft approached the island, the pilots relied on the light from a lighthouse and a single illuminated house for navigation. The captain decided to perform a steep approach to avoid obstacles such as rocks and skerries. During this maneuver, the pilots disconnected the autopilot and began descending.
As the helicopter approached the water, the co-pilot noted the altitude had dropped below 100 feet. Moments later, the winch operator observed the aircraft rapidly approaching the waves and shouted a warning. However, the captain misheard the warning due to the phonetic similarity between the Swedish words for "moving backwards" and "watch out." The helicopter struck the water surface, causing it to fill rapidly with water and capsize. While most of the crew evacuated successfully, the captain became trapped in the cabin and had to use a portable breathing apparatus to escape before the aircraft sank to a depth of 8 meters.
The investigation
The Swedish Accident Investigation Board (SHK) examined the aircraft's technical state, the crew's performance, and the airline's operational protocols. The investigation looked into the use of available cockpit technology, including the radar, radio altimeter, and GPS. The board also reviewed the company's flight manuals and the effectiveness of the crew's communication during the terminal phase of the flight.
Findings
- The pilots underestimated the high level of difficulty involved in landing at an unestablished site in darkness with limited visual references.
- The lack of adequate operational routines and procedures for this specific type of mission was a primary factor.
- Available technical aids, such as the radar and radio altitude warning system, were intentionally switched off or set to levels that provided no useful warning during the descent.
- The crew did not follow existing company procedures, such as performing a 360-degree circuit to orient themselves or briefing the crew on the landing plan.
- The airline's standard operating procedures for HEMS flights were found to be insufficient for managing the risks of night-time VFR operations in remote areas.