What happened
A skill-test was being conducted for a new first officer candidate for the operator Helitostrans. The flight took place at Bergen Airport Flesland under challenging meteorological conditions involving IMC, rain, and significant winds. During the flight, which involved demonstrating slow flight and stall characteristics, the crew lost control of the aircraft's attitude and airspeed. Despite applying full power, the airspeed dropped to approximately 30 kt, and a high sink rate of 10,000 ft/min developed. The SA226-T(B) Merlin struck the sea in a near horizontal position roughly 37 seconds after control was lost. There were 3 fatalities among the crew on board.
Findings
Investigations revealed that the Stall Avoidance and Stability Augmentation System (SAS) circuit breaker had not been reset following a previous flight, which was confirmed during the start-up check. The commander had previously pulled this breaker to prevent nuisance activations of the stick pusher caused by turbulence. While CFD analysis indicated that external sensors and antennas on the aircraft did not significantly degrade stability in slow flight, the crew's inability to maintain control in IMC was a critical factor. The accident was driven by the decision to conduct airwork in unsuitable weather conditions, combined with the lack of visual references in the clouds and the presence of atmospheric turbulence.