The Tenerife airport disaster occurred on March 27, 1977, when two Boeing 747 passenger jets collided on the runway at Los Rodeos Airport (now Tenerife North Airport) on the Spanish island of Tenerife.

The deadliest aviation accident in history occurred on March 27, 1977, on the runway of Los Rodeos Airport (now Tenerife North Airport) in the Canary Islands. The disaster involved the collision of two Boeing 747s: KLM Flight 4805 and Pan Am Flight 1736. A total of 583 people perished in the crash. The accident was caused by a "perfect storm" of unfortunate events, including heavy fog that reduced visibility to almost zero, a bomb at a nearby airport that forced both planes to divert to the smaller Tenerife airport, and critical communication misunderstandings. The KLM pilot, believing he had takeoff clearance, began his roll down the runway while the Pan Am jet was still "back-taxiing" directly in his path. The collision and subsequent fires were catastrophic. This tragedy fundamentally changed aviation history, leading to the global adoption of Crew Resource Management (CRM), which encourages co-pilots to challenge captains' decisions, and the implementation of standardized, unambiguous English phraseology for all Air Traffic Control communications.