The world's worst aviation disaster in history happened on March the 27th, 1977, on the island of Tenerife, in the Canary Islands. 2 Boeing 747s, KLM Flight 4805- (the flight crew were: CAP- Jacob van Zanten, F/O- Klaas Meurs, F/E- William Schreuder, with 234 passengers and 11 cabin crew), and Pan Am Flight 1736- (the flight crew were: CAP- Victor Grubbs, F/O- Robert Bragg, F/E- George Warns, with 380 passengers and 11 cabin crew), collided on the runway after a diversion due to a terrorist bomb detonation at Gando Airport, serving Las Palmas on the island of Gran Canaria, their original destination.

Beacause of the bomb, dozens of aircraft, along with both the KLM and Pan Am 747s were diverted to Los Rodeos airport, 35 minutes from Las Palmas. However 15 minutes after the Pan Am 747's arrival at Los Rodeos, Gando Airport is reopened. However due to stress from newly introduced company time limits, the KLM's flight crew decide to refuel, taking on 55 tons of fuel to cut down on turnaround times at Gando Airport. This delays both them and the Pan Am 747 for 35 minutes. 

During that time the weather changes. Since Los Rodeos airport is at 2000 feet elevation, the airport is always covered in thick fog. To make matters worse the airport had no ground radar at the time, and the runway center lights were not working on that day either. At 4:56 p.m local time, the KLM 747 is told to taxi down to the end of the runway, turn 180 degrees and wait for take-off clearance. Minutes later the Pan Am 747 is also told to taxi down the runway, but turn off onto the taxiway to let the KLM 747 depart.

At 5:04 p.m the KLM 747 reaches the end of the runway, where the KLM flight crew are given their Air Traffic Control clearance- (this is the route the plane must follow after taking off. NOT permission to take-off). By then the Pan Am 747 is still on the runway, 1 kilometre in front, well beyond their minimum visibility range- [minimum visibility required was 700 meters, but the fog reduced visibility to 500 meters.]. Then at 5:06 p.m, in spite of having not received take-off clearance, KLM Flight 4805 begins it's take-off run.

At 5:06 p.m and 45 seconds, the Pan Am 747 reaches the access lane for the taxiway and begins turning off. But as the Pan Am 747's co-pilot Robert Bragg looked out the window he was horrified. The 335-ton KLM 747 was heading straight for them!

Upon seeing each other both flight crews reacted. The Pan Am crew pushed their throttles forward to power the 747 off the runway. At the same time the KLM plane tries to lift off the ground. But the 55 tons of fuel it had taken on earlier made it too heavy. The KLM plane's tail scraped the runway as the plane tried to lift off, which it only did just when it was a few meters from the Pan Am 747. On the Pan Am 747, co-pilot Robert Bragg yelled "Get off, Get off". But it was too late.

5 seconds after seeing each other, both 747s collided. The KLM plane's nose and nose wheel cleared the Pan Am 747, but sadly it's engines and undercarriage did not. The left wing and no. 1 engine struck the Pan Am 747's tail, tearing off half the left wing. The KLM's landing gear smashed into the middle of the Pan Am's fuselage, while the KLM's no. 3 engine struck the Pan Am 747's upper deck and it's no. 4 engine sliced off the Pan Am's cockpit roof. After the impact the KLM plane flew on for 700 feet, and slammed into the ground 1500 feet from where the Pan Am 747 was. Tragically neither any of the KLM 747's 8 fuselage doors were opened, nor an emergency evacuation command was given on that plane, before the 55 tons of fuel ignited immediately, killing everyone on board.

Out of the 394 people on Pan Am 1736, 70 people got out alive, including all 3 pilots. Unfortunately 9 of the Pan Am survivors had fatal injuries and died few days later. This brought the final body count to a staggering 583 fatalities, more than any previous aviation accident.
tenerife disaster