Investigation
About 70 crash investigators from Spain, the Netherlands, the United States, and the two airline companies were involved in the investigation. Facts showed that there had been misinterpretations and false assumptions. Analysis of the CVR transcript showed that the KLM pilot was convinced that he had been cleared for takeoff, while the Tenerife control tower was certain that the KLM 747 was stationary at the end of the runway and awaiting takeoff clearance. It appears KLM's co-pilot was not as certain about take-off clearance as the captain.
Subsequent to the crash, first officer Robert Bragg, who was responsible for handling the Pan Am's radio communications, made public statements which conflict with statements made by the Pan Am crew in the official transcript of the CVR. In the documentary Crash of the Century (produced by the makers of Mayday), he stated he was convinced the tower controller had intended they take the fourth exit C-4 because the controller delivered the message to take "the third one, sir; one, two, three; third, third one" after the Pan Am had already passed C-1 (making C-4 the third exit counting from there). The CVR shows unequivocally that they received this message before they identified C-1, with the position of the aircraft somewhere between the entrance and C-1. Also, in a Time article, Bragg stated that he made the statement "What's he doing? He'll kill us all!" which does not appear in the CVR transcript.
Read more about this topic: Tenerife Airport Disaster