What happened
On April 7, 2016, at 18:36 central daylight time, a runway incursion occurred at Dallas-Fort Worth International Airport (DFW). An American Airlines Boeing 737-80 0 (AAL2408) was performing a takeoff roll on runway 35L when an Embraer 505, registration N304QS, crossed the same runway downfield. At the time of the closest proximity, the Boeing 737-800 was traveling at approximately 120 knots, and the distance between the two aircraft was roughly 2,800 feet. There were no injuries to the passengers or crew of either flight.
Prior to the event, the pilot of N304QS had landed on runway 35C and was instructed to taxi to the terminal. The local control east controller (LE1) directed the pilot of N304QS to hold short of runway 35L on taxiway K8. During this period, the controller also issued crossing clearances for runway 35L to three different aircraft.
At 18:35:14, the LE1 controller issued a takeoff clearance for a different flight (AAL2304). Eight seconds later, the controller instructed the pilot of AAL2408 to line up and wait on runway 35L. The pilot of AAL2408 responded with a takeoff clearance readback, which the controller did not correct. As AAL2408 began its takeoff roll, the Runway Status Lights (RWSLs) activated, illuminating the Runway Entrance Lights (RELs) for the aircraft holding short and the Takeoff Hold Lights (THLs) at the approach end of the runway. However, AAL2408 had already progressed too far down the runway to observe the THLs. The N304QS proceeded to cross runway 35L while the Boeing 737-800 was departing.