A catastrophic accident occurred on the runways of Madrid–Barajas Airport when an Iberia Airlines Boeing 727 and an Aviaco DC-9 collided in extremely dense fog conditions. The incident unfolded as the two aircraft were attempting to taxi simultaneously. The limited visibility, which often plagues the airport during specific weather conditions, played a critical role in the miscommunication and ultimately the collision. This tragic incident highlighted significant issues in air traffic control protocols and ground operations for commercial airliners during inclement weather, emphasizing the need for improved safety measures in the aviation industry.

The collision resulted in the deaths of 93 individuals, drawing widespread attention to the vulnerabilities present in airport operations. Eyewitness accounts described the chaos ensuing from the impact, with emergency crews rushing to the scene under challenging conditions due to fog. Both aircraft were heavily damaged, and the aftermath saw significant investigations launched to determine fault and prevent future incidents. This alarming accident prompted aviation authorities to review existing safety regulations and operational guidelines, particularly in regions prone to severe weather.

In the months following the disaster, airlines and regulatory agencies around the world examined the protocols for taxiing under limited visibility, implementing enhanced training for flight crews and ground staff. The event became a critical case study in aviation safety discussions, leading to advancements in technology and procedures aimed at preventing similar accidents from occurring in the future.