Dfw tower controller reported clearing an aircraft for takeoff while another aircraft was taxiing ac...

Narrative:

I was working local control position with the other local control split off from my position. I had crossed aircraft X over both runways 18R and 18L. I had crossed him over both because I had some space due to a cro (converging runway operation) aircraft arriving runway 13R. Aircraft X took longer to cross than I had anticipated and he hadn't finished crossing runway 18L when I scanned my runway. I was out of my normal flow due to the cro and I was trying to get my next departure out before the next aircraft entered the cro box for runway 13R. I completely forgot about aircraft X crossing and cleared aircraft Y for departure. Aircraft Y started takeoff roll and aircraft X was crossing. Aircraft Y saw aircraft X and aborted his takeoff roll. I then issued the existing instructions to aircraft Y. I got too focused getting my departures out and watching final for runway 18R and got out of my normal rhythm.when aircraft are arriving runway 13R I prefer to have an assist position instead of splitting of the local control position. I feel like the extra set of eyes in this situation may have helped me and slowed me down some. I also think that having someone work the push towards the end of their time on position is not ideal; I prefer to work at the beginning of the push through the whole push so that I am at my most aware and ready.

Original NASA ASRS Text

Title: DFW Tower Controller reported clearing an aircraft for takeoff while another aircraft was taxiing across the runway. First Officer of aircraft taking off also reported seeing aircraft crossing runway.

Narrative: I was working Local Control position with the other Local Control split off from my position. I had crossed Aircraft X over both Runways 18R and 18L. I had crossed him over both because I had some space due to a CRO (Converging Runway Operation) aircraft arriving Runway 13R. Aircraft X took longer to cross than I had anticipated and he hadn't finished crossing Runway 18L when I scanned my runway. I was out of my normal flow due to the CRO and I was trying to get my next departure out before the next aircraft entered the CRO box for Runway 13R. I completely forgot about Aircraft X crossing and cleared Aircraft Y for departure. Aircraft Y started takeoff roll and Aircraft X was crossing. Aircraft Y saw Aircraft X and aborted his takeoff roll. I then issued the existing instructions to Aircraft Y. I got too focused getting my departures out and watching Final for Runway 18R and got out of my normal rhythm.When aircraft are arriving Runway 13R I prefer to have an assist position instead of splitting of the Local Control position. I feel like the extra set of eyes in this situation may have helped me and slowed me down some. I also think that having someone work the push towards the end of their time on position is not ideal; I prefer to work at the beginning of the push through the whole push so that I am at my most aware and ready.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1665863
Time
Date	201907
Local Time Of Day	1201-1800
Place
Locale Reference	DFW.Airport
State Reference	TX
Environment
Light	Daylight
Aircraft 1
Make Model Name	Medium Large Transport
Operating Under FAR Part	Part 121
Flight Phase	Taxi
Flight Plan	IFR
Aircraft 2
Make Model Name	Large Transport
Operating Under FAR Part	Part 121
Flight Phase	Takeoff
Route In Use	None
Flight Plan	IFR
Person 1
Function	Local
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 10.0
Person 2
Function	First Officer Pilot Flying
Experience	Flight Crew Total 10000
Events
Anomaly	ATC Issue All Types Conflict Ground Conflict Critical

Dfw tower controller reported clearing an aircraft for takeoff while another aircraft was taxiing across the runway. First officer of aircraft taking off also reported seeing aircraft crossing runway.