Date: 201603
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Aircraft: Bonanza 36
Operator: Personal
Operating under: Part 91
Flight plan: IFR
Mission: Personal
Flight phase: Descent
Airspace: Class C ZZZ
ATC / advisory: TRACON ZZZ; Tower ZZZ
Reporter organization: Government
Reporter function: Instructor; Local
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Training / Qualification; Situational Awareness; Confusion
Second reporter function: Trainee; Approach
Anomaly: Airspace Violation All Types; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Runway; Inflight Event / Encounter Weather / Turbulence
Detector: Person Air Traffic Control
When detected: Taxi
Result: Air Traffic Control Provided Assistance; Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Airport; Airspace Structure; Human Factors; Weather
Primary problem: Human Factors

Narrative: I was training a developmental on the Local Control position at ZZZ. The weather was VFR but there was rain on the field and heavy precipitation and thunderstorms in the vicinity. Aircraft X checked in on our frequency inbound from the Northwest on a Visual Approach. At the time Aircraft X was one to two miles northwest of the airport (ZZZ1) which his flight path would take him directly over as he joined the final. However; instead of continuing inbound for RWY 18; the pilot descended to land at ZZZ1.The approach controller called us to verify that Aircraft X was still inbound to the correct airport at which point the developmental reached out to Aircraft X to let him know he was still 5 miles from ZZZ and to verify he had the correct airport in sight. The pilot seemed confused so at this point I took over the frequency. I asked the pilot if he had landed or was continuing inbound for ZZZ. It was difficult to hear everything the pilot said as the Local Control frequency at ZZZ is not meant for use on the ground at ZZZ1 but the pilot did verify that he was on the ground. I requested he cancel IFR; advised that ZZZ was no longer reporting VFR weather and issued the approach frequency for ZZZ1 so that he could call approach if he wanted to continue to ZZZ IFR. A short time later Aircraft X contacted TRACON and departed ZZZ1 on a special VFR clearance for ZZZ where he landed without incident.Contributing factors on our part included training and weather conditions. The developmental I was training is low on hours and told me he had never worked in adverse weather conditions before. Because of this we spent a good deal of time on position discussing the radar weather display; non-standard procedures and ways to be flexible when storms arrive. When Aircraft X initially contacted us; the developmental was in the process of clearing an air carrier jet for takeoff. This involved putting the aircraft in position; suggesting a heading and giving the pilot time to review his own weather radar in case he wanted to request a different initial heading. When an acceptable departure heading was decided on; the developmental coordinated the heading with departure and cleared the jet for takeoff. This process and the questions it led to from the developmental took some of our attention away from the aircraft on final. Also; as the pilot was already at a low altitude when he checked on and was expected to fly directly over ZZZ1; it did not take long for him to descend and land.I'm not sure if the weather played a role in the pilot's confusion but it may not have been wise to clear him for a visual approach when the weather was marginal VFR and likely to become IFR. We were advertising instrument approaches but the pilot had requested a visual approach. While not necessarily a procedural change; I will do my best in the future to check with any aircraft flying low level and on a flight path close to ZZZ1 to ensure they have the correct airport in sight. I would also suggest emphasizing the vicinity of ZZZ1 to ZZZ in the classroom curriculum so that developmental controllers are also aware of the possible confusion.


Second narrative: I came to work and was told that I would be training on radar positions today. The last time I trained was (over 30 days ago). Trainer and I received a briefing and Aircraft X began to flash northwest of my airspace. I took the handoff then told the aircraft to expect ILS Approach. There was a line of precipitation about 9 miles west of ZZZ moving slowly east so I told Aircraft X about the weather. After looking at the winds which were approximately 140/10G18; I asked him if he would prefer an RNAV Approach. He said yes so I told him to expect RNAV approach.I told him to proceed direct [fix 1] (IAF) but he said [fix 2] (FAF) was already dialed in and asked if he could proceed direct [fix 2]. I approved his request since I planned on clearing him for Visual Approach. After I gave him a descent clearance to 2;000 feet; he told me he would be able to do a Visual approach. I told him the airport was 1 o'clock; 13 miles. He said Roger. I gave him another update and said the airport was 1 o'clock; 10 miles. He came back and said he had the field in sight and would proceed inbound via [fix 2]. I cleared Aircraft X for a Visual Approach via [fix 2] and instructed him to contact Tower.I then noticed his data tag scratchpad was showing [a runway designation]; so I mentioned it to my trainer; but he did not say anything. So I thought one of the Tower controllers did that; so I rolled my chair across the aisle to the CRU-ART computer to see who was working Local Control. I saw there was training in Local Control also. When I rolled back to the scope; I noticed the data block for Aircraft X was no longer on the radar scope.The aircraft never reached [fix 2] and apparently thought ZZZ was the airport next to [fix 2]. I immediately called the Tower and asked them if he landed at the wrong airport. The Tower tried to reach him and called me back after confirming he had landed. I told the Supervisor who was seated at his desk. When the pilot reports having the airport in sight; verify he is looking at ZZZ and not ZZZ1. Also; the trainer was still seated at the other scope but apparently did not see the aircraft start his descent. The MSAW never alarmed; which could have alerted us the aircraft was descending rapidly. The pilot never indicated he was unfamiliar with the area and ZZZ1.My recommendations:Ask the pilot if he is familiar with the area and ZZZ1 airport's position and similarity to ZZZ. If he is not familiar; continue to watch aircraft until passing ZZZ1 airport before switching him to Tower. When cleared for the Visual Approach; keep him on frequency Tower should also watch the aircraft's altitude for any changes around ZZZ1 when inbound on a visual approach. The FLIP should highlight the fact that ZZZ1 and ZZZ airport are [very similar] in layout and pilots should exercise caution when inbound to either airport.


Synopsis: Several Air Traffic Controllers reported an aircraft on a Visual Approach that landed at the wrong airport.