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Cases › CEN19MA141 · Major investigation · Class 1

De Havilland DHC-2Mountain Air Service LLC

Ketchikan, AK, USA · 2019-05-13·N952DB

6
fatal
9
serious
Fatal
highest injury
Destroyed
damage
AnalyseThe analystOne timeline · precedents · ask the docket · what the record saysGenerateInvestigation briefFacts, cause, recorder extremes, sequence, sourcesSourceNTSB docket0 documents on data.ntsb.gov

What happened

NTSB summary, verbatim

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.

Photographs

1the aircraft, and what the investigators found
The aircraft before the accident
N952DB DHC-2 Beaver Ketchikan 04-09-15 (21684674196)
Rob Hodgkins · CC BY-SA 2.0 · Wikimedia Commons

Probable cause

the Board's determination
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 Administration’s 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.

Occurrence sequence

2 stepsNTSB coding · CICTT taxonomy
  1. 1 · Maneuvering
    Midair collision
    defining event
  2. 1 · Maneuvering
    Midair collision
    defining event

Findings

12 causal · 5 contributing
  • CAUSE
    Personnel issues › Physical › Sensory ability/limitation › Visual function — Pilot
  • CAUSE
    Personnel issues › Physical › Sensory ability/limitation › Visual function — Pilot
  • CAUSE
    Personnel issues › Physical › Sensory ability/limitation › Visual function — Pilot of other aircraft
  • CAUSE
    Personnel issues › Physical › Sensory ability/limitation › Visual function — Pilot of other aircraft
  • CAUSE
    Aircraft › Aircraft systems › Indicating/recording systems › Central warning — Not specified
  • CAUSE
    Aircraft › Aircraft systems › Indicating/recording systems › Central warning — Not specified
  • CAUSE
    Organizational issues › Development › Selection/certification/testing › Equip certification/testing — FAA/Regulator
  • CAUSE
    Organizational issues › Development › Selection/certification/testing › Equip certification/testing — FAA/Regulator
  • CAUSE
    Aircraft › Aircraft systems › Navigation system — Design
  • CAUSE
    Aircraft › Aircraft systems › Navigation system — Design
  • CAUSE
    Organizational issues › Management › Policy/procedure › Adequacy of policy/proc — FAA/Regulator
  • CAUSE
    Organizational issues › Management › Policy/procedure › Adequacy of policy/proc — FAA/Regulator
  • FACTOR
    Environmental issues › Task environment › Pressures/demands › Equipment/operational — Effect on operation
  • FACTOR
    Environmental issues › Task environment › Pressures/demands › Equipment/operational — Effect on operation
  • FACTOR
    Aircraft › Aircraft systems › Navigation system — Incorrect use/operation
  • FACTOR
    Organizational issues › Management › Policy/procedure › Adequacy of policy/proc — Operator
  • FACTOR
    Organizational issues › Support/oversight/monitoring › Safety programs — FAA/Regulator

NTSB analysis

from the final report

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.