What happened
On August 9, 2015, a De Havilland DHC-2 Beaver, registration N610LC, was conducting a ferry flight from Akureyri to Keflavik, Iceland, as part of a larger journey to the United States. The flight was being operated under Visual Flight Rules (VFR). During the flight, the crew encountered deteriorating weather conditions, including low cloud ceilings and fog, which prevented them from crossing the mountain ridges of Öxnadalsheiði and Hörgárdalsheiði.
After being forced to turn around twice due to the cloud base, the pilots spotted a potential break in the clouds over the head of the Barkárdalur valley. They made a spontaneous decision to enter the narrow valley. As the aircraft attempted to execute a turn within the valley, it lost altitude and crashed at an elevation of approximately 2,260 feet. The pilot survived the impact with severe injuries, but the ferry flight pilot was fatally injured in a post-crash fire.
The investigation
The RNSA investigation focused on the aircraft's performance, the meteorological conditions, and the decision-making process of the crew. Investigators analyzed the aircraft's weight and balance, noting that the aircraft was operating significantly above its maximum gross weight of 5,090 lbs. The investigation also examined the climb performance of the aircraft under these overweight conditions and the impact of the rising valley floor on the pilots' perception of altitude.
Findings
- The aircraft was overweight, which significantly degraded its climb performance and maneuverability.
- The crew attempted to fly in marginal weather conditions where VFR visibility was not maintained across the intended route.
- Carburetor icing likely contributed to the loss of engine performance.
- The pilots experienced a loss of situational awareness regarding their height above terrain because the valley floor was rising rapidly, masking their actual altitude loss.
- The pilot's selection of an airspeed that was too low for the aircraft's weight and bank angle caused the power required to exceed the power available, leading to the fatal loss of altitude.