What happened
On May 13, 2019, at approximately 12:21 Alaska daylight time, a midair collision occurred between two float-equipped aircraft northeast of Ketch and 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 area.
Both aircraft were traveling toward a scenic waterfall in the Mahoney Lakes region of Revillagigedo Island. According to ADS-B tracking data, the de Havilland DHC-3 was flying at approximately 4,000 feet MSL and began a descent around 12:19. Simultaneously, the de Havilland DHC-2 was climbing through 3,175 feet. The two planes collided at an altitude of 3,350 feet, roughly 7.4 nautical miles northeast of the Ketchikan Harbor Seaplane Base.
The impact caused the de Havilland DHC-2 to break into several pieces before hitting the water and terrain. The de Havilland DHC-3 experienced a sudden vertical load factor change and entered a steep right bank and nose-down attitude before eventually impacting George Inlet. The collision resulted in 5 fatalities (the pilot and four passengers of the de Havilland DHC-2, plus one passenger from the de Havilland DHC-3) and 9 serious injuries.
Findings
At the time of the accident, visual meteorological conditions were present. The pilot of the de Havilland DHC-3 reported that while checking the traffic display, they observed other aircraft groups that were not on their direct flight path, but they did not observe the de Havilland DHC-2 on the display prior to the impact.