What happened
On May 13, 2019, at approximately 12:21 Alaska daylight time, a midair collision occurred between two float-equipped aircraft northeast of Ketchikan, Alaska. The first aircraft, a de Havilland DHC-2 (registration N952DB) operated by Mountain Air Service LLC, was performing an on-demand sightseeing flight. The second aircraft, a de Havilland DHC-3 (registration N959PA) operated by Taquan Air, was also conducting a sightseeing flight in the same area.
Both aircraft were maneuvering near the Mahoney Lakes area on Revillagigedo Island, heading toward a waterfall in the Misty Fjords National Monument before their return to the Ketchikan Harbor Seaplane Base. At the time of the incident, visual meteorological conditions were present. ADS-B tracking data showed the de Havilland DHC-3 was descending from 4,000 feet while the de Havilland DHC-2 was climbing through 3,175 feet. The two planes collided at an altitude of 3,350 feet.
The impact caused the de Havilland DHC-2 to break into several pieces, which then struck the water and terrain. The de Havilland DHC-3 experienced a sudden vertical load factor upset and entered a steep right bank and nose-down attitude before eventually impacting George Inlet. The collision resulted in 5 fatalities and 10 injuries, including one death among the passengers of the de Haviliand DHC-3 and five deaths among the occupants of the de Havilland DHC-2.
Findings
Data from the de Havilland DHC-3 avionics indicated that the pilot observed other traffic on the traffic display, but noted the targets were not on his direct flight path. The pilot stated he did not see the de Havilland DHC-2 on his display prior to the impact. The collision occurred as the two aircraft were on converging tracks.