This created stress and frustration for all air crews involved. Also, it was a Sunday so only two air traffic controllers were on duty. They were not acustomed to so much traffic and especially not with only two of them. Then was the line management faulty. This was the lack of signage on the runway. The Pan Am airline had no knowledge of the airport design and it made it even more difficult with the lack of vision due to the weather. They did not know where to turn off the runway. This meant they missed their turnoff and went to the next one. They were on the runway longer than they should have been. The precondition error was made by the Pan Am pilot saying he was clear of the runway when he was not. This then lead to the productive activity of the pilot taking off without take off clearance as he had runway clearance. This was the most fatal decision made. It was an incredibly unexpected move made as this pilot is the most well known pilots and the top pilot in the industry. He went to take off once and the co-pilot (whom the pilot trained) told him not to as they did not have takeoff clearance but then the pilot went again and the co-pilot did not speak up. The last line of defences was that the KLM aircraft filled up on fuel while they were waiting. This meant that the aircraft required more speed for V1 and rotate to life it off the ground. It also increases landing and take off distances. [ CITATION Pat14 l 1033 ] When the pilot of the KLM was attempting to take off, he noticed the other aircraft on the runway but it was too late to stop. Due to the increase in take off distance, the aircraft smashed straight through the Pan Am aircraft killing 583 people. [ CITATION PBS12 l 1033 ] To this day it is still the worst aviation distaster in histroy. Even though there were many factors causing the crash, it all came down to pilot error and taking off when he was not cleared to do so. This was a human error.