Investigation of an aviation accident in Vinddalsvatnet outside Bergen in Vestland county

The flight with the light aircraft was an instructional flight in acro flying with an instructor and a student. The student was part of a training program for acro flying privileges.

Earlier that day, the instructor had flown back and forth from Flesland to Stord Airport Sørstokken to pick up the student. The accident flight departed at 15:02 local time. The plan for the flight was to perform various acrobatic exercises over Bjørnafjorden. After completing the exercises, they were to land at Flesland.

After completed the aerobatic manouvres, they contacted the air traffic control. According to a recording of this communication, the pilot declared Mayday. He stated that they had an engine failure, and said they planned to make an emergency landing in a lake.

Helicopter resources in nearby airspace, was scrambled by ATC. They started search, without making any positive identification of the aircraft or wreckage parts from the aircraft.

Divers from the Norwegian Navy EOD Command carried out the search and later assisted with lifting the wreckage out of the sea. The search for the wreckage was conducted using sonar and then the wreckage was inspected using video from a remotely operated underwater vehicle (ROV). The police were responsible for the deceased pilots. They were brought up before the recovery of the wreckage began.

The day after the accident, a fuel cap was found on the runway at Flesland. The accident aircraft has two fuel tanks, one in each wing with their own fuel cap. Images from the ROV showed that the fuel cap on the left wing was missing. 

The left wing fuel tank. Photo: MDK, Haakonsvern

During the recovery, it was already verified that the fuel cap that had been found on the runway, belonged to the accident aircraft, and it was put in place on the aircraft before the recovery.

Fuel cap beloning to LN-SDB found at ENBR. Photo: Avinor

It cannot be concluded so far that the lack of fuel caused engine problems. The investigation authority is therefore examining the engine and associated systems to find or rule out errors.

The investigation authority has confirmed that fuel was filled in the morning at Flesland, prior to the flight to Stord.

The NSIA has opened a full investigation into the accident.

The investigation will clarify the sequence of events and the contributing factors to the accident. Based on this, the NSIA will assess areas for improving safety.

It is not the NSIA’s task to apportion blame or liability under criminal or civil law. The purpose of the investigation is solely to contribute to learning and the prevention of serious incidents and accidents.

The Norwegian Safety Investigation Authority (NSIA) has completed its investigation into the aviation accident at Vinddalsvatnet on 1 April 2025.

The investigation has included technical examinations of the aircraft, its engine and fuel system, as well as a review of electronic tracking data, radio communications and other collected material. NSIA has also assessed operational aspects of the flight, including fuel management, pre-flight inspections, the emergency landing and the evacuation following the accident.

A draft report has been circulated to the parties concerned for external review. This is an important part of the quality assurance process and helps identify any factual inaccuracies, misunderstandings or matters that may require further investigation before the report is finalized. NSIA is now assessing the comments received and will publish the final report once this work has been completed.

Latest update: 07.08.2026