Narrative:

I was working local. I told air carrier Y to XXXX after traffic had crossed threshold. After traffic exited; I inadvertently cleared air carrier X to land instead of air carrier Y to takeoff. I did not notice my error. After a bit of time I became concerned air carrier Y was not rolling and it was getting close. Ground controller questioned whether I had in fact cleared air carrier Y to takeoff. I cleared him for immediate. Distance was not sufficient for takeoff so I cancelled takeoff clearance and sent air carrier X around. I did not think I was capable of such a wrong transmission in the first place.

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Original NASA ASRS Text

Title: Tower Controller described a runway conflict when failing to note that incorrect clearances were issued to the landing and departing aircraft.

Narrative: I was working Local. I told Air Carrier Y to XXXX after traffic had crossed threshold. After traffic exited; I inadvertently cleared Air Carrier X to land instead of Air Carrier Y to takeoff. I did not notice my error. After a bit of time I became concerned Air Carrier Y was not rolling and it was getting close. Ground Controller questioned whether I had in fact cleared Air Carrier Y to takeoff. I cleared him for immediate. Distance was not sufficient for takeoff so I cancelled takeoff clearance and sent Air Carrier X around. I did not think I was capable of such a wrong transmission in the first place.

Data retrieved from NASA's ASRS site as of July 2013 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.