On the morning of June 30 , 1956 , United Flight 718 collided with TWA Flight 2 over the Grand Canyon , resulting in 128 deaths , which was at the time the largest loss of life in an aviation accident . This high-profile accident , which took place in uncontrolled airspace , raised public concern for airline safety . In 1957 Congress passed the Airways Modernization Act that established the Airways Modernization Board ( AMB ) headed by General Elwood Quesada
United Flight 718 collided with TWA Flight 2
1956 Grand Canyon mid-air collision
Federal Aviation Act of 1958