Narrative:

I was working both locals combined during the planning stages of a runway change. We were on a west operation landing runway xxr and runway xy. We were going to go to runway xxl and runway yy and I was informed of the last xxr arrival. An aircraft reported hitting a fox on runway xxr which closed the runway and I sent the first guy around on final and was able to side step the rest of the arrivals to runway xxl. I had 2 departures for xxl; I cleared the first one in between arrivals and the second one was aircraft X. Since we were going to be departing runway xxr soon; ground control was instructed to start taxiing aircraft to runway xxr which was closed at the time due to the fox being hit. After an arrival touched down I told aircraft X to line up and wait. He did just that; but subsequently aircraft Y [similar callsign to aircraft X] took runway xxr. The supervisor must have taken the closed runway X's off the runway because I never recalled the airport releasing the runways back to the tower. I cleared aircraft X for takeoff on runway xxl and both aircraft started rolling. I immediately told aircraft Y to stop and exit the runway and told aircraft X he could roll. Both aircraft slowly exited the runway and the next arrival for runway xxl was sent around. I do not have any recommendations for this event; they were similar sounding call signs but the one concern I had was why would the supervisor take the X's off the runway if the runway was still closed which would dismantle that feature of the safety logic. Luckily I was able to stop aircraft Y from taking off of a closed runway.

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Original NASA ASRS Text

Title: Tower Controller and Air Carrier Captain reported taking closed runway resulting in RTO due to similar callsign with another aircraft.

Narrative: I was working both locals combined during the planning stages of a runway change. We were on a west operation landing runway XXR and runway XY. We were going to go to runway XXL and runway YY and I was informed of the last XXR arrival. An aircraft reported hitting a fox on runway XXR which closed the runway and I sent the first guy around on final and was able to side step the rest of the arrivals to runway XXL. I had 2 departures for XXL; I cleared the first one in between arrivals and the second one was Aircraft X. Since we were going to be departing runway XXR soon; ground control was instructed to start taxiing aircraft to runway XXR which was closed at the time due to the fox being hit. After an arrival touched down I told Aircraft X to line up and wait. He did just that; but subsequently Aircraft Y [similar callsign to Aircraft X] took runway XXR. The supervisor must have taken the closed runway X's off the runway because I never recalled the airport releasing the runways back to the tower. I cleared Aircraft X for takeoff on runway XXL and both aircraft started rolling. I immediately told Aircraft Y to stop and exit the runway and told Aircraft X he could roll. Both aircraft slowly exited the runway and the next arrival for runway XXL was sent around. I do not have any recommendations for this event; they were similar sounding call signs but the one concern I had was why would the supervisor take the X's off the runway if the runway was still closed which would dismantle that feature of the safety logic. Luckily I was able to stop Aircraft Y from taking off of a closed runway.

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.