Do you know that the deadliest accident in aviation history actually happened on the ground? In 1977, two fully loaded planes carrying a total of over 600 passengers collided head-on in the middle of the runway in what is now known as the Tenerife Accident, named after Tenerife Island where the accident occurred.
The Tenerife airport disaster was a fatal runway collision between two Boeing 747s on Sunday, March 27, 1977, at Los Rodeos Airport (now Tenerife North Airport). The crash killed 583 people, making it the deadliest accident in aviation history. As a result of the complex interaction of organizational influences, environmental preconditions, and unsafe acts leading up to this aircraft mishap, the disaster at Tenerife has served as a textbook example for reviewing the processes and frameworks used in aviation mishap investigations and accident prevention.
A bomb explosion at Gran Canaria Airport and the threat of a second bomb caused many aircraft to be diverted to Los Rodeos Airport. Among them were KLM Flight 4805 and Pan Am Flight 1736 – the two aircraft involved in the accident. At Los Rodeos Airport, air traffic controllers were forced to park many of the airplanes on the taxiway, thereby blocking it. Further complicating the situation, while authorities waited to reopen Gran Canaria, dense fog developed at Tenerife, greatly reducing visibility.
When Gran Canaria reopened, the parked aircraft blocking the taxiway at Tenerife required both of the 747s to taxi on the only runway in order to get in position for takeoff. The fog was so thick that neither aircraft could see the other, and the controller in the tower could not see the runway or the two 747s on it. As the airport did not have ground radar, the controller could find where each airplane was only by voice reports over the radio. As a result of several misunderstandings, the KLM flight tried to take off while the Pan Am flight was still on the runway. The resulting collision destroyed both aircraft, killing all 248 aboard the KLM flight and 335 of 396 aboard the Pan Am flight. Sixty-one people aboard the Pan Am flight, including the pilots and flight engineer, survived the disaster.https://www.youtube.com/embed/kjLrZ2SDDaU
The investigation revealed that the primary cause of the accident was the captain of the KLM flight taking off without clearance from Air Traffic Control. The investigation specified that the captain did not intentionally take off without clearance; rather he fully believed he had clearance to take off due to misunderstandings between his flight crew and ATC. The accident had a lasting influence on the industry, particularly in the area of communication.