Narrative:

I was working all locals combined during routine runway inspections/closures. Aircraft X was taxiing to rwy 30L; and aircraft Y was on final for runway 35. Because aircraft Y was about to enter the 35 adw [arrival departure window] I instructed aircraft X to line up and wait on 30L and received a good read back. Aircraft X still had a ways to taxi and it appeared that the wait in position would be minimal before aircraft Y exited the adw. I did not give aircraft X a reason why they were put into position. I did my normal scan and checked 30R to see the progress of the vehicles for the 30R closure. After scanning the radar for aircraft Y's progress through the adw (they were in the middle of the adw); I looked out on the runway and noticed aircraft X in their takeoff roll. They were about 1000 feet down the runway and had enough speed that I felt aborting their departure roll would be a less safe option rather than turning them north if aircraft Y went around. I issued aircraft X a takeoff clearance with a runway head[ing] to provide some control when they were in the air. When I was confident that the situation was resolved I turned aircraft X on the appropriate heading and sent them to departure. When working 30s/35 cro [converging runway operations] I normally only issue a reason for being in position to wait for the adw when there is another aircraft on the final for the 30's. I do this so the pilots do not get anxious about being on the runway when they know there is someone landing behind them. In the future; I need to issue it to all aircraft in this configuration; regardless of demand on the parallels. Although aircraft X rolled on their own; I feel that the fact that I didn't explain the reason for aircraft X's luaw [line up and wait] contributed to them rolling on 30L with an aircraft in the 35 adw.

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Original NASA ASRS Text

Title: MSP Tower Controller reported that an aircraft was told to line up and wait but took off in error while an arrival was in the Arrival Departure Window.

Narrative: I was working all locals combined during routine runway inspections/closures. Aircraft X was taxiing to Rwy 30L; and Aircraft Y was on final for runway 35. Because Aircraft Y was about to enter the 35 ADW [Arrival Departure Window] I instructed Aircraft X to line up and wait on 30L and received a good read back. Aircraft X still had a ways to taxi and it appeared that the wait in position would be minimal before Aircraft Y exited the ADW. I did not give Aircraft X a reason why they were put into position. I did my normal scan and checked 30R to see the progress of the vehicles for the 30R closure. After scanning the radar for Aircraft Y's progress through the ADW (they were in the middle of the ADW); I looked out on the runway and noticed Aircraft X in their takeoff roll. They were about 1000 feet down the runway and had enough speed that I felt aborting their departure roll would be a less safe option rather than turning them north if Aircraft Y went around. I issued Aircraft X a takeoff clearance with a runway head[ing] to provide some control when they were in the air. When I was confident that the situation was resolved I turned Aircraft X on the appropriate heading and sent them to departure. When working 30s/35 CRO [Converging Runway Operations] I normally only issue a reason for being in position to wait for the ADW when there is another aircraft on the final for the 30's. I do this so the pilots do not get anxious about being on the runway when they know there is someone landing behind them. In the future; I need to issue it to all aircraft in this configuration; regardless of demand on the parallels. Although Aircraft X rolled on their own; I feel that the fact that I didn't explain the reason for Aircraft X's LUAW [Line Up And Wait] contributed to them rolling on 30L with an aircraft in the 35 ADW.

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.