Date: 201303
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Aircraft: Any Unknown or Unlisted Aircraft Manufacturer
Flight plan: IFR
Flight phase: Final Approach
Airspace: Class B ZZZ
ATC / advisory: Tower ZZZ
Reporter organization: Government
Reporter function: Local
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Communication Breakdown; Human-Machine Interface
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Executed Go Around / Missed Approach
Contributing factors: Human Factors; Procedure
Primary problem: Human Factors

Narrative: The aircraft was a business jet. I was working Local North; Local Center; and had also picked up Local South approximately 10 minutes into this session. Traffic was not busy. I noticed the aircraft on final for Runway 27 and walked to where I could get a complete visual scan of that runway (I was working from the Local Center position.) I had been working several aircraft to these two runways but the business jet may have been the first aircraft I had for Runway 27 since I had picked up the position. I reached out to contact the aircraft without success. I then heard a partial call over the Guard frequency that sounded like either all or part of the call sign was used. I had reached out to the aircraft more than once as I had not noticed the pilot check in. I heard the Guard frequency when the aircraft was inside the final approach fix. I grabbed a light gun and notified the Supervisor and Local West about a possible go-around. I at some point called down to the final position to have them try the aircraft again to switch to my frequency. I noticed the aircraft also had entered a second beacon code of 7606. I was assuming the pilot had tried entering 7600 for radio failure. I had notified Local West early on that we were not talking to the aircraft and kept the Local West Controller advised. The Supervisor did issue a landing clearance over the Guard frequency at my request. The aircraft did not respond. I had also handed a light gun to another Supervisor who was in a better position to issue the Cleared to land light signal. The light gun was given probably around a three mile final. During this time I had been trying to navigate on the touch screen that we use for frequencies and communications. I found myself on a page I didn't want and was trying to bring up the guard frequency page; when the Supervisor issued the landing clearance on Guard. I also switched pages when trying to call the final controller. The aircraft did not react to either the Green Light or the Guard call and initiated a go-around. All Local positions had been given a heads up early on and there were not any loss of separation issues. The aircraft then checked on to the Local West frequency during the go-around. At that time I clicked back to my main frequency page and noticed that the Local South frequency was not selected. I figure I must have forgotten to select the frequency when I picked up Local South or I had hit something wrong while navigating the touch screen. I am thinking it is highly likely that I never had it selected. Either way the Local West Controller vectored the aircraft and cleared the aircraft to land. I may have forgotten to select the frequency. Recommendation; briefings that something be verbally stated about the frequencies being selected when combining positions; other information on the check lists. Pilots should be reminded to be looking for light gun signals in situations involving communication issues. Pilots should also be monitoring guard frequencies.




Synopsis: Tower Controller described a go around event when communication with an arrival was not established. The reporter later realized the appropriate frequencies were not selected after positions were combined.