Tower controller described a potential loss of separation event immediately following a local contro...

Narrative:

I was working local 1 and the volume of traffic was rapidly getting heavier. I requested a local 2. I assigned aircraft X; inbound from the southeast; runway xxr; he read it back verbatim. I later sequenced him but cleared him for runway xxl. I then split off local 2; who now owned runway xxr; told him that aircraft X was cleared to land on runway xxr; then switched aircraft X to the local 2 frequency. I then cleared aircraft Y for take off on runway xxl. The pilot of aircraft Y asked if I had someone on final. Aircraft X was on a 3/4 mile final. Local 2 keyed up and sent aircraft X around; but he did not respond and landed anyway. Aircraft Y never entered runway xxl and remained on the taxiway short of the runway. Recommendation; be more aware of rapidly progressing traffic and call for a local 2 or a cc earlier so that I would have had someone else listening to me and helping me.

Original NASA ASRS Text

Title: Tower controller described a potential loss of separation event immediately following a Local Control position split; failing to note his/her changed runway assignment; causing the incident.

Narrative: I was working Local 1 and the volume of traffic was rapidly getting heavier. I requested a Local 2. I assigned Aircraft X; inbound from the Southeast; Runway XXR; he read it back verbatim. I later sequenced him but cleared him for Runway XXL. I then split off Local 2; who now owned Runway XXR; told him that Aircraft X was cleared to land on Runway XXR; then switched Aircraft X to the Local 2 frequency. I then cleared Aircraft Y for take off on Runway XXL. The pilot of Aircraft Y asked if I had someone on final. Aircraft X was on a 3/4 mile final. Local 2 keyed up and sent Aircraft X around; but he did not respond and landed anyway. Aircraft Y never entered Runway XXL and remained on the taxiway short of the runway. Recommendation; be more aware of rapidly progressing traffic and call for a Local 2 or a CC earlier so that I would have had someone else listening to me and helping me.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	926249
Time
Date	201101
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Tower
State Reference	US
Aircraft 1
Make Model Name	Cessna Aircraft Undifferentiated or Other Model
Flight Phase	Initial Approach
Person 1
Function	Local
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy

Tower controller described a potential loss of separation event immediately following a local control position split; failing to note his/her changed runway assignment; causing the incident.