Accident Summary
A float-equipped air taxi airplane was departing from a remote bay 20 miles north of Ketchikan, Alaska, to return passengers after a ground tour. The accident resulted in multiple fatalities: five passengers, including two children, were killed at the scene, and a sixth passenger died from injuries about a month later.
Flight Details
The pilot, who reported 17,000 flight hours with 7,000 hours in the accident make and model, noted that southeasterly winds had increased while waiting for passengers. Unlike when he landed 2.5 hours earlier, conditions were no longer calm. The pilot observed choppy waves in a nearby cove and elected to take off toward the interior of the bay, in the direction of rising terrain—a departure he had never attempted before.
He initially planned a shallow right-climbing turn toward the bay mouth, but after takeoff, he saw numerous choppy waves along that path, which he interpreted as indicating strong winds. He changed his plan, flying straight temporarily to avoid the waves, and then initiated a left 180-degree turn inside the bay, which was surrounded by high terrain. The pilot reported the airplane was about 400 feet above the water when the turn began, but he did not recall the airspeed. The 180-degree turn was within the airplane's capabilities but placed it closer to rising terrain.
During the turn, the airplane encountered a downdraft, stalled about 60 feet above the ground, and was unable to climb above the terrain. The downdraft likely made it more difficult to avoid descending.
Weather Conditions
A National Transportation Safety Board weather study confirmed a gust front in the area and an abrupt wind change around the accident time. Pilots flying nearby reported low-level windshear, strong winds, and turbulence.
Probable Cause
The official probable cause is an inadvertent aerodynamic stall resulting from the pilot's poor decision-making and inadequate planning and execution when he took off toward nearby rising terrain, in strong winds, under circumstances where his options for maneuvering were severely limited and where his safety margin was, thus, insufficient.