NTSB · Safety Recommendation
Safety Recommendation A-21-017
Recommendation
TO THE FEDERAL AVIATION ADMINISTRATION: Require the installation of Automatic Dependent Surveillance-Broadcast Out- and In-supported (ADS-B) 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.
Safety Issue and Context
On May 13, 2019, about 1221 Alaska daylight time, a float-equipped de Havilland DHC-2 (Beaver) airplane, N952DB, and a float-equipped de Havilland DHC-3 (Otter) airplane, N959PA, collided in midair about 8 miles northeast of Ketchikan, Alaska. The DHC-2 pilot and four passengers sustained fatal injuries. The DHC-3 pilot sustained minor injuries, nine passengers sustained serious injuries, and one passenger sustained fatal injuries. The DHC-2 was destroyed and the DHC-3 sustained substantial damage.
The DHC-2 was registered to and operated by Mountain Air Service LLC, Ketchikan, Alaska, under the provisions of Title 14 Code of Federal Regulations (CFR) Part 135 as an on-demand sightseeing flight. The DHC-3 was registered to Pantechnicon Aviation LTD, Minden, Nevada, and operated by Venture Travel, LLC, dba Taquan Air, Ketchikan, Alaska, under the provisions of Part 135 as an on-demand sightseeing flight. Visual meteorological conditions prevailed in the area at the time of the accident.
According to information provided by the operators, both airplanes had been conducting sightseeing flights and were both converging on a scenic waterfall before returning to the Ketchikan Harbor Seaplane Base (5KE), Ketchikan, Alaska, when the accident occurred. Automatic dependent surveillance-broadcast (ADS-B) tracking data for both airplanes revealed that, at 1217:15, 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 (nm) south of the DHC-3, climbing through 2,800 ft msl, on a track of 255°.1 About 1219, the DHC-3 started a descent from 4,000 ft, and the DHC-2 was at 3,175 ft 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 on a track of about 255°. The airplanes collided at 1221:14 at an altitude of 3,350 ft, 7.4 nm northeast of 5KE.
Response History
February 17, 2026 · NTSB Correspondence · FAA
From the Aviation Investigation Report AIR-26-02, “Midair Collision over the Potomac River PSA Airlines Flight 5342, Mitsubishi Heavy Industries (MHI) RJ Aviation CL-600-2C10 (CRJ700), and US Army Priority Air Transport Flight 25, Sikorsky UH-60L Washington, DC January 29, 2025”
1.15.3 ADS-B The NTSB also has a long history of supporting the use of technologies, such as ADS-B, that provide identification and location information for aircraft due to the ability of these technologies to improve safety. Between 2006 and 2007, we recommended requirements for equipment that could provide increased aircraft identification, location, and communication capabilities for aircraft operations in the Gulf of America and remote areas of Hawaii and Alaska, with the intent of enhancing flight location, collision avoidance, and weather information services for these operations (see Safety Recommendations A-06-21 and -22, and A-07-025 and -26; NTSB, 2006; NTSB, 2007a).
Following the 2006 midair collision involving a business jet and a transport category airplane over Brazil that claimed 154 lives, we recommended requirements for equipment that could provide pilots with enhanced alerts regarding the status of transponder and traffic collision avoidance capabilities (Safety Recommendations A 07-35 through -37; NTSB, 2007b).
Following the 2007 fatal midair collision of two news-gathering helicopters over Phoenix, Arizona, the NTSB sought to enhance the traffic-avoidance logic for helicopters’ onboard equipment by recommending the development of standards and requirements for the incorporation of specific criteria for the types of maneuvers and environments unique to helicopters (Safety Recommendations A 09 4 and -5, superseded by Safety Recommendations A 10 127 and -128; NTSB 2009; NTSB, 2010).
In an October 2007 notice of proposed rulemaking to require ADS B Out, the FAA stated that it did not plan to also require ADS-B In capability because ADS-B In “has not been identified as a requirement for maintaining the safety and efficiency of NAS operations.” In a letter dated February 14, 2008, in response to this notice of proposed rulemaking, the NTSB expressed our belief that this assessment was incorrect and stated that equipping aircraft with ADS-B In capability would