The investigation into the fatal crash of a Sikorsky S-92 off the coast of Norway in February is focusing on why the aircraft’s nose pitched up to about a 30-degree attitude shortly before it hit the water, the Norwegian Safety Investigation Authority (NSIA) said in the latest update on its work.
The Bristow-operated search-and-rescue (SAR) aircraft was performing a training flight at the time of the accident, with six crewmembers on board. The crash into the freezing waters of the North Sea claimed the life 61-year-old SAR nurse Reidun Hestetun, and the NSIA said its investigation is also exploring the issue of survivability.
While the aircraft was equipped with floats — and they were armed at the time of the crash — they did not deploy when the aircraft hit the sea. The NSIA said the flotation system is designed to work in a controlled emergency landing — and had previously noted that the accident “cannot be described as a controlled emergency landing.”
“When the main rotor blades hit the sea, the power supply required for automatic deployment stopped and thus prevented the possibility of an automatic deployment of the flotation elements,” the NSIA said in its latest update.
It noted that new international regulations with emergency flotation elements for helicopters have been published with an implementation date of August 2025.
“The S-92 helicopter type will have to undergo modifications to satisfy these new regulations,” the NSIA said.
A routine training flight
On Feb. 28, the aircraft was performing a SAR training mission about two nautical miles west of Løno, Norway. The crew dropped a training Emergency Position-Indicating Radio Beacon into the sea, which was to be searched for later.
The flight then continued north, where the crew practiced hoist operations with a ship. They then returned towards the beacon, and were positioning to retrieve it when the accident happened.
“It was dark with few external visual references,” the NSIA said, adding that the flight was carried out according to visual flight regulations without the use of night vision goggles. There was a southerly 35-knot wind.
The crew had activated the “mark on top” mode of the automatic flight control system. According to data recovered from the flight data recorder, HUMS information, and data from the flight control computer, the aircraft’s pitch attitude “started to increase abnormally” when the aircraft was about 150 feet above the training beacon.
“The nose of the helicopter started to rise from the expected 10- to 12-degree nose-up attitude to a 30-degree nose-up attitude over several seconds,” the NSIA said. “When the crew became aware of the situation, they attempted to correct the unusual attitude, however the aircraft impacted the water and sank to a depth of 220 metres.”
Two helicopters were used in the rescue.
“One person was found floating without a deployed life jacket and any sign of life when the first rescue helicopter arrived at the accident site,” the NSIA said. “Life jackets used in helicopters must be deployed manually. It was therefore prioritized to pick up the five survivors.”
With one of the survivors in critical condition, the rescue helicopter took them to hospital. The second helicopter, which arrived “somewhat later,” recovered Hestetun’s body, the NSIA said.
It said its investigation will therefore also explore “the possibility of evacuation, the rescue operation itself, and the crew’s personal equipment.”
