What happened
On June 4, 2023, a private Aviat Husky A-1A, registration LN-AAK, departed from Bandak in the Tokke municipality for a flight toward Kragerø. After performing a standard pre-flight inspection and engine warm-up on the water, the pilot began an eastbound-southeastbound departure along the lake.
To avoid high-voltage power lines spanning the lake, the pilot intended to maintain an altitude of approximately 100 feet above the water surface while flying close to the shoreline. While the takeoff initially appeared normal, video footage from witnesses showed the aircraft gradually losing altitude. Shortly before impact, the pilot attempted to pull back on the controls, but the aircraft struck the water with significant force. The impact caused the left float strut to collapse, resulting in the propeller striking the front edge of the left float.
Following the impact, the pilot sustained minor injuries to the left side of the upper body after being thrown against the cockpit door. The aircraft's engine stopped 48 seconds after the water impact. Bystanders in small boats arrived to assist, eventually towing the aircraft to the shore, though the aircraft was heavily tilted with the left wingtip submerged during the process.
The investigation
The Norwegian Safety Investigation Authority (NSIA) examined the flight path and the environmental conditions at the time of the accident. The investigation noted that the water surface was extremely calm and glassy, which can make it difficult to judge altitude using only visual references. The investigation also reviewed the pilot's maneuver intended to clear the power lines, which were positioned at a height of approximately 259 feet above the water.
Findings
- The pilot relied solely on visual references to maintain altitude over the water, which is particularly challenging over a glassy water surface.
- The flight was conducted at an altitude lower than the 500-foot minimum required by visual flight rules (VFR) for navigating near obstacles.
- The decision to maintain a low altitude to pass under power lines increased the risk of an uncontrolled descent into the water.