Narrative:

Aircraft X called on frequency 5 miles southeast of the airport. The pilot advised me that this was the first time in. I ensured the ATIS code and tried to get the pilot to do a 360 degree turn and then right traffic. I had just cleared 3 to 4 aircraft for takeoff and most of the flight paths would be in conflict with the inbound aircraft. I advised the aircraft to make a 360 turn then right traffic. I figured that would give the aircraft some room for descent as well. I observed the aircraft going north. I located the aircraft out the window and figured maybe it be best I give the pilot someone to follow. I turned my pattern aircraft Y. I told aircraft X to make a left turn and make left traffic for 4L and maintain at or above 3000 feet for traffic. Once the aircraft was on the left downwind I approved descent to pattern altitude and issued traffic to follow. I cleared aircraft X to land on 4L. I was worried he would mistake runway 4R so I told him the north runway; the short one. Aircraft Y landed and exited the runway to the left and I instructed him to hold short of runway 4L at taxiway E2. I watched aircraft X line up on final. It looked like the aircraft was lined up. An aircraft called to tell me he lost his traffic I looked away and saw him in the downwind and issued his traffic on base. Then I cleared the next aircraft in the downwind. I returned my scan to aircraft X who was landing and realized he was on echo taxiway. I thought of aircraft Y I had on taxiway echo and keyed up to tell them to get out of the way. I saw him on bravo taxiway and that was a moment of relief. If I had told aircraft X to go around it would have still been a conflict with aircraft Y. I will not say north runway or describe which runway it is. I thought I was helping to ensure he wouldn't land on the closed runway. The view line is difficult to determine whether or not an aircraft is lined up for the correct runway sometimes. There are times when helicopter operations appear to line up to the runway while they are actually lined up to the taxiway.

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Original NASA ASRS Text

Title: FFZ Local Controller and the associated pilot reported that an aircraft had mistakenly landed on a taxiway instead of the assigned runway.

Narrative: Aircraft X called on frequency 5 miles southeast of the airport. The pilot advised me that this was the first time in. I ensured the ATIS code and tried to get the pilot to do a 360 degree turn and then right traffic. I had just cleared 3 to 4 aircraft for takeoff and most of the flight paths would be in conflict with the inbound aircraft. I advised the aircraft to make a 360 turn then right traffic. I figured that would give the aircraft some room for descent as well. I observed the aircraft going north. I located the aircraft out the window and figured maybe it be best I give the pilot someone to follow. I turned my pattern Aircraft Y. I told Aircraft X to make a left turn and make left traffic for 4L and maintain at or above 3000 feet for traffic. Once the aircraft was on the left downwind I approved descent to pattern altitude and issued traffic to follow. I cleared Aircraft X to land on 4L. I was worried he would mistake Runway 4R so I told him the North runway; the short one. Aircraft Y landed and exited the runway to the left and I instructed him to hold short of Runway 4L at taxiway E2. I watched Aircraft X line up on final. It looked like the aircraft was lined up. An aircraft called to tell me he lost his traffic I looked away and saw him in the downwind and issued his traffic on base. Then I cleared the next aircraft in the downwind. I returned my scan to Aircraft X who was landing and realized he was on Echo taxiway. I thought of Aircraft Y I had on taxiway Echo and keyed up to tell them to get out of the way. I saw him on Bravo taxiway and that was a moment of relief. If I had told Aircraft X to go around it would have still been a conflict with Aircraft Y. I will not say North runway or describe which runway it is. I thought I was helping to ensure he wouldn't land on the closed runway. The view line is difficult to determine whether or not an aircraft is lined up for the correct runway sometimes. There are times when helicopter operations appear to line up to the runway while they are actually lined up to the taxiway.

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.