Narrative:

Aircraft X was on an approach to runway xx. ZZZ [approach] changed aircraft X to an approach to runway xxl to help a help another aircraft turn ahead of them for a [runway] xy approach. Aircraft X turned out the west. I saw the aircraft turning out to the west and fly through the final for runway xxl and runway xxr outside of my airspace. Aircraft X then turned back east toward the airport. I was launching airplanes and trying to be an extra set of eyes for lce [local control east] who was very busy at the time being combined with [xyz position]. Aircraft X then checked on to my frequency for runway xxl and I cleared them to land runway xxl. They appeared to still be southeast toward runway xxl. As I noticed they may be lined up for the incorrect runway ZZZ approach called and asked me check as well. I informed the pilot they were lined up for the wrong runway and they chose to go around on about a 3 mile final.some of my focus was on aiding the traffic for lce. If we had more staffing we could have had a [xyz] controller aiding with that.

Google
 

Original NASA ASRS Text

Title: Tower Controller reported an aircraft lined up for the wrong runway during approach.

Narrative: Aircraft X was on an approach to Runway XX. ZZZ [Approach] changed Aircraft X to an approach to Runway XXL to help a help another aircraft turn ahead of them for a [Runway] XY approach. Aircraft X turned out the West. I saw the aircraft turning out to the West and fly through the final for Runway XXL and Runway XXR outside of my airspace. Aircraft X then turned back East toward the airport. I was launching airplanes and trying to be an extra set of eyes for LCE [Local Control East] who was very busy at the time being combined with [XYZ position]. Aircraft X then checked on to my frequency for Runway XXL and I cleared them to land Runway XXL. They appeared to still be SE toward Runway XXL. As I noticed they may be lined up for the incorrect runway ZZZ Approach called and asked me check as well. I informed the pilot they were lined up for the wrong runway and they chose to go around on about a 3 mile final.Some of my focus was on aiding the traffic for LCE. If we had more staffing we could have had a [XYZ] Controller aiding with that.

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.