Common Themes

Human Error

Errors were made by numerous individuals. The most important of these was the KLM captain's decision to takeoff with another aircraft on the active runway.

  • The KLM captain, in his haste to depart, did not wait for takeoff clearance before beginning his takeoff roll.
  • The tower controller did not immediately understand the KLM first officers' statement "We are now at takeoff" to mean that the KLM aircraft had started its takeoff. When he did realize this he stated, "Stand by for takeoff ... I will call you." However, this was not clearly heard in the KLM cockpit.
  • The Pan Am crew did not exit the runway via the taxiway given by the tower controller, Taxiway Charlie Three. Instead the crew may have assumed, due to the configuration of the airport, that the controller meant for them to exit via the more easily navigated fourth taxiway. 

Unintended Effects

Previous duty time regulations allowed a captain some flexibility in extending duty time. A new Dutch law, enacted in 1976, removed a crew's flexibility in compliance. Further, if duty time were exceeded, a captain could be held liable for criminal prosecution. The law had originally been intended as a means to improve safety by assuring that flight crews were adequately rested, remained alert for the duration of a flight, and capable of good decision making. The unintended effect, in the case of the Tenerife accident, was exactly the opposite. According to the accident report, the captain became preoccupied with duty time limitations, and was approaching a time deadline, after which the flight would have to be cancelled. The investigation concluded that his preoccupation with not exceeding the deadline may have resulted in his poor decision making, and led to a series of unsafe actions that resulted in the accident.

Back to top