Here’s something to chew on the next time your flight is cleared for takeoff.
NTSB animation of runway incursion by 747 into path of 737 taking off at O’Hare
What happened:
Controller “A” was working arriving traffic from a peticular area. They cleared Atlas to land on 14R.
Controller “B” was working departures on 27L. He had UAL1015 position and hold on 27L. When UAL called ready for takeoff, the controller checked around for conflicting traffic and did not see any. Last he heard about Atlas, he was on a 5 mile final. What he did not see due to his view being blocked by another person standing up in the tower was Atlas rolling out from a landing on 14R. He cleared UAL1015 for takeoff not knowing that Atlas was rolling out from a landing on 14R.
UAL started their takeoff roll. They saw the Atlas 747 approaching the runway and obviously not stopping. The captain stated he had two choices. Steer off the runway to the right behind the Atlas striking the many obstacles and soft ground going 120kts, or pull up and hope you clear it. He felt they could climb over it so thats the choice he made. The UAL’s Vr speed was 143kts. He rotated before even reaching V1, around 125kts and climbed like hell as clearly illustrated in the animation. He estimates he cleared the Atlas by 100ft.
The folks in the tower saw the two aircraft heading for eachother and alerted controller B. He yelled STOP STOP STOP and at that point, UAL was already preying to Our Lady of The Blessed Acceleration and lifting off. It was too late to stop anyway.
UAL asked atlas on the radio why they didn’t hold short. Atlas replied “nobody told us to!”.
Controller B in his interviews with the NTSB gave an exact account for everything he did and admitted to it being his fault. He clearly felt very bad. What also came out of the interview process of everyone involved was that even if he did see Atlas, he may very well have assumed Atlas was going to be turning off long before crossing 27L. The whole incident unvailed a lot of things that happen on a routine basis that are concidered “normal procedure” that can cummulate and lead to this near disaster. Thankfully, Our Lady of The Blessed Acceleration as with the crew of UAL1015 that day.