NTSB preliminary reports do not draw conclusions as the cause of a crash. But the NTSB’s preliminary report of the Turbine Otter crash that killed 9 near Ketchikan on June 25 suggests a weather-related “CFIT” crash, exactly as described here.
First, the report indicates that the flight was conducted under Visual Flight Rules. That means that that pilot was supposed to stay out of the clouds and avoid the terrain by looking out the window rather than by relying on instruments.
Second, the report indicates that the closest reported weather was “marginal” for flying under visual flight rules. (“The closest weather reporting facility is Ketchikan Airport (KTN), Ketchikan, AK, about 24 miles southwest of the accident site. . . few clouds 800 feet, broken clouds 1,200 feet, overcast clouds 2,700 feet. . .”)
Third, and most significantly, a helicopter pilot searching for the aircraft minutes after the crash was unable to get to the crash site because the terrain was obscured by clouds and fog.
The NTSB noted that the Otter was equipped with a moving map display that is designed to depict the aircraft’s position with respect to hazardous terrain. When first introduced, such displays were seen as a boon to safety, making it easier for pilots to avoid terrain that they might not otherwise be able to see. But some argue that such technology doesn’t increase safety at all, because pilots use the technology to fly closer to the edge than they otherwise would. The phenomenon coming into play is called “risk homeostasis.” And in fact, the NTSB has previously found that aircraft equipped with moving maps and the other technology comprising modern "glass cockpits" have a higher rate of fatal accidents than those that aren’t.