Overview

On August 10, 2018, a Horizon Air Bombardier Dash 8 Q400 left Seattle–Tacoma International Airport without authorization and later crashed on Ketron Island. The event began on the ground at Seattle–Tacoma International Airport in SeaTac, Washington and ended after a short flight over Puget Sound. The incident attracted widespread public attention because the person who took the aircraft was not a trained pilot.

Person and aircraft

The aircraft was a Bombardier Dash 8 Q400, a twin‑engine turboprop commonly used on regional routes. Its systems and controls are designed for professional flight crews; however, a person with ground‑operations knowledge can perform basic engine start and taxi procedures. The individual responsible, a 29‑year‑old Horizon Air ground service agent, had no formal piloting credentials.

Sequence of events

After moving the aircraft into position and starting its engines, the agent taxied, took off and flew a series of turns and climbs over the Puget Sound area. During the flight, civilian air traffic control maintained radio contact with him, and military aircraft — reported as F-15 fighter jets — were scrambled to intercept and monitor the airplane. The flight ended with a crash on Ketron Island, a sparsely populated landmass in the sound; the pilot died in the wreckage.

Investigation and responses

Federal investigators examined security procedures, ramp access controls and how ground personnel could operate aircraft systems without supervision. The incident prompted reviews by aviation authorities and the airline industry of airport access rules, employee screening, and safeguards to prevent unauthorized use of aircraft.

Legacy and significance

Beyond the immediate tragedy, the event raised questions about airport security, mental health and the resilience of aviation procedures when non‑crew personnel exploit operational knowledge. It remains a case study in the interplay between human factors and technical systems in civil aviation.

  • Aircraft type: Bombardier Dash 8 Q400 (twin turboprop regional airliner)
  • Operator: Horizon Air
  • Location: Seattle–Tacoma International Airport and Ketron Island