Narrative:A float-equipped DHC-3 Turbine Otter (N959PA of Taquan Air) and a float-equipped DHC-2 Beaver (N952DB of Mountain Air Service) collided in midair, about 7 miles northeast of Ketchikan, Alaska, USA. The five occupants of the DHC-2 sustained fatal injuries. The DHC-3 pilot sustained minor injuries, nine passengers sustained serious injuries, and one passenger sustained fatal injuries.
The purpose of both flights was to transport passengers to Ketchikan from the Misty Fjords National Monument area in Alaska, USA. Both flights were converging on a scenic waterfall before returning to the Ketchikan Harbor Seaplane Base.
At 12:17:15, the DHC-3 was about level at 4,000 ft mean sea level (msl) on a track of 225°, and the DHC-2 was 4.2 nautical miles south of the DHC-3, climbing through 2,800 ft msl, on a track of 255°. About 12:19, the DHC-3 started a descent from 4,000 ft msl, and the DHC-2 was at 3,175 ft msl and climbing. During the next 1 minute 21 seconds, the DHC-3 continued to descend on a track between 224° and 237°, and the DHC-2 leveled out at 3,350 ft msl on a track of about 255°. The airplanes collided at 12:21:14 at an altitude of 3,350 ft msl, 7.4 nm northeast of Ketchikan Harbor.
The DHC-3 pilot stated to the NTSB that the flight from the Misty Fjords area had proceeded normally, and he had descended and was maneuvering the airplane to show passengers a waterfall near Mahoney Lake when the collision occurred. Just prior to the collision, he saw a flash from his left side, and experienced a large, loud impact. According to the pilot, the DHC-3 airplane then rolled right and pitched about 40 degrees nose down toward the water in George Inlet. The pilot stated that he was able to maintain some control and flare the airplane prior to impact. The pilot, some passengers, and some bystanders helped the passengers of the DHC-3 evacuate the airplane and move to the shore. The DHC-3 main wreckage came to rest about 80 ft underwater about 400 ft off the east shore of George Inlet.
The DHC-2 airplane broke up in-flight after the collision, and the wreckage was scattered over water and mountainous tree-covered terrain northeast of Mahoney Lake on the west shore of George Inlet.
Both aircraft were ADS-B-equipped and both pilots were presented with visual traffic information through the iPad with ForeFlight app (DHC-2) and Chelton display (DHC-3). However, the Garmin GSL 71 on the DHC-3 had been turned off, causing pressure altitude of the airplane not to be transmitted with the ADS-B data. Thus, both systems were not able to generate warnings of potential conflicts.
Additionally, the DHC-2 was obscured from the Otter pilot's vision by the window frame until the very last moment. The Beaver pilot likely was unable to see the Otter approaching from behind due to the aircraft structure and the passenger seated on his right.
Probable Cause:
Probable Cause:
The National Transportation Safety Board determines that the probable cause of this accident was the inherent limitations of the see-and-avoid concept, which prevented the two pilots from seeing the other airplane before the collision, and the absence of visual and aural alerts from both airplanes traffic display systems, while operating in a geographic area with a high concentration of air tour activity. Contributing to the accident were (1) the Federal Aviation Administrations provision of new transceivers that lacked alerting capability to Capstone Program operators without adequately mitigating the increased risk associated with the consequent loss of the previously available alerting capability and (2) the absence of a requirement for airborne traffic advisory systems with aural alerting among operators who carry passengers for hire.
Accident investigation:
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Investigating agency: | NTSB  |
Status: | Investigation completed |
Duration: | 2 years | Accident number: | AAR-21-04 | Download report: | Final report
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Sources:
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KTUU.com»
KTVA.com» ADN.com
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Coast Guard statement
Follow-up / safety actions
NTSB issued 10 Safety Recommendations
Issued: 13-MAY-2021 | To: FAA | A-21-15 |
Identify high-traffic air tour areas and require, through a special federal aviation regulation or other means, that Title 14 Code of Federal Regulations Parts 91 and 135 air tour operators that operate within those areas be equipped with an Automatic Dependent Surveillance-Broadcast Out- and In-supported traffic advisory system that 1) includes both visual and aural alerts, 2) is driven by an algorithm designed to minimize nuisance alerts, and 3) is operational during all flight operations. |
Issued: 13-MAY-2021 | To: FAA | A-21-16 |
In the high-traffic air tour areas identified in Safety Recommendation A-21-15, require that all nonair tour aircraft operating within the airspace be equipped with Automatic Dependent Surveillance-Broadcast Out. |
Issued: 13-MAY-2021 | To: FAA | A-21-17 |
Require the installation of Automatic Dependent Surveillance-Broadcast Out- and In-supported airborne traffic advisory systems that include aural and visual alerting functions in all aircraft conducting operations under Title 14 Code of Federal Regulations Part 135. |
Issued: 13-MAY-2021 | To: FAA | A-21-18 |
Review current and future supplemental type certificate installation instructions and flight manual supplements to ensure they provide provisions to prevent the inadvertent disabling of the broadcast of pressure altitude data, by design, where practicable. |
Issued: 13-MAY-2021 | To: FAA | A-21-19 |
Ensure that checklists for all Capstone Program (phase 2) aircraft include verification that the Garmin GSL 71 control head selector knob is in the ON position and that the unit is in ALT mode before takeoff. |
Issued: 13-MAY-2021 | To: FAA | A-21-20 |
Update the Aeronautical Information Manual and the Pilots Handbook of Aeronautical Knowledge to include the limitations inherent in visual scans for traffic and the benefits and best practices of using cockpit displays of traffic information to supplement visual scans to help overcome these limitations. |
Issued: 13-MAY-2021 | To: ForeFlight | A-21-21 |
Update your traffic alerting algorithms so that traffic targets for which there is no altitude information are assumed to be at the same altitude as the ownship (that is, the aircraft receiving the target data). |
Issued: 13-MAY-2021 | To: Taquan Air | A-21-22 |
Revise the checklists for your fleet of aircraft to ensure they include verification that the Garmin GSL 71 control head selector knob is in the ON position and that the unit is in ALT mode before takeoff. |
Issued: 13-MAY-2021 | To: aviation industry groups | A-21-23 |
Inform your members about the circumstances of this accident and encourage them to take the following actions: (1) become familiar with the traffic display equipment installed in their aircraft; (2) if their equipment does not provide an aural alert concerning proximate targets that might pose a collision threat, encourage pilots/operators to supplement the equipment with devices that provide both an aural and visual alert; and (3) remind pilots to include the traffic display when scanning for traffic through the aircrafts windows. |
Issued: 13-MAY-2021 | To: National Association of Flight Instructors | A-21-24 |
Inform your members of the circumstances of this accident and incorporate instruction on including the traffic display when scanning for traffic through an aircrafts windows in both initial and recurrent pilot training. |
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Photos

Preliminary ADS-B track data

accident date:
13-05-2019type: de Havilland Canada DHC-3T Vazar Turbine Otter
registration: N959PA
Video, social media
Map
This map shows the airport of departure and the intended destination of the flight. The line between the airports does
not display the exact flight path.
Distance from Rudyerd Bay, AK to Ketchikan Harbor Seaplane Base, AK as the crow flies is 66 km (41 miles).
Accident location: Exact; deduced from official accident report.
This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.