The Grand Canyon mid-air collision occurred when Grand Canyon Airlines Flight 6, a de Havilland Canada DHC-6 Twin Otter, collided with a Bell 206 helicopter, Helitech Flight 2, over Grand Canyon National Park on June 18, 1986. All 25 passengers and crew on board the two aircraft were killed. It remains the deadliest accident involving a helicopter on United States soil, surpassing the crash of Los Angeles Airways Flight 841 in 1968, which killed 23 people.
