Investigation and aftermath
The
National Transportation Safety Board investigation found that N4891F, the Piper, had deviated into the LAX
Terminal Control Area. It was out of radio contact with air traffic control, which had been distracted by another flight entering his control area without having received clearance.
Moreover, the Piper was not equipped with a Mode C
transponder, which would have indicated its altitude, and LAX had not been equipped with automatic warning systems. Finally, apparently neither pilot sighted the other aircraft because neither attempted any evasive maneuvers, even though they were in visual range. When an autopsy revealed significant arterial blockage in the heart of the Piper's pilot, there was public speculation that he had suffered a
heart attack, causing incapacitation and contributing to the collision; however, further forensic evidence discounted this, and error on the part of the Piper pilot was determined to be the main contributing factor to the collision.
[5]
As a result of this accident and other near mid-air collisions (NMAC) in terminal control areas, the
Federal Aviation Administration required that all commercial aircraft be equipped with traffic alert and collision avoidance systems (
TCAS), and required that light aircraft operating in dense airspaces be equipped with "Mode C" transponders that could report three-dimensional position.
[8]
A jury ruled that the
Aeroméxico plane bore no fault, instead deciding that Kramer and the FAA each acted equally negligently and had equal responsibility. U.S. District Judge David Kenyon agreed with the notion that the FAA shared responsibility.