Date: 201605
Local time of day: 1201-1800
Location: ARR.Airport, IL
Light: Daylight
Aircraft: Citation V/Ultra/Encore (C560)
Flight plan: IFR
Flight phase: Descent
Airspace: Class D ARR
ATC / advisory: Tower ARR
Second aircraft: Skyhawk 172/Cutlass 172
Reporter organization: Government
Reporter function: Local
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Workload; Troubleshooting; Situational Awareness; Communication Breakdown; Confusion; Distraction; Human-Machine Interface
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Took Evasive Action
Contributing factors: Human Factors; Procedure
Primary problem: Human Factors

Narrative: Aircraft X was making a visual approach landing to RWY 33 while Aircraft Y and another aircraft were the left VFR traffic pattern for RWY 27. I had visually observed Aircraft X enter the radar scope from southeast of the airport. Prior to that time and prior to my taking position; the previous controller had switched the active runway from RWY 33 to RWY 27. Immediately after there were 3 aircraft that entered the traffic pattern for RWY 27 requesting touch and goes. In addition to that traffic; there where multiple VFR departures awaiting at RWY 27 for departure outside of ARR's airspace as well as a couple arrivals to the south and north of the field. After the departures took off and the inbound VFR aircraft landed; there were still three aircraft in the pattern for RWY 27. The ground controller had not updated the IDS4 [Information Display System 4] to that ARR was now using RWY 27 as the active runway and RNAV 27 as the active approach. I had forgotten that RNAV Runway 33 was still showing as the approach. As Aircraft X entered my scope from the southeast I planned for him to be number 2 behind an aircraft on half mile final. When Aircraft X checked on he simply stated he was on the visual approach. I told him to slow to final speed and that he was number two for the runway behind the previously mentioned traffic. I then cleared him to land RWY 27. Then Aircraft X read back cleared to land. I advised Aircraft Y of the traffic he was following to RWY 27. As Aircraft Y approached midfield left downwind RWY 27; I observed that Aircraft X was not turning toward the east to enter a left base to RWY 27. Aircraft X stated that Aircraft Y had come at him almost head on and that he was making an approach to RWY 33. I cleared Aircraft X to land RWY 33 and advised Aircraft Y of the crossing RWY traffic and cleared him to land and hold short RWY 33. Both aircraft then landed without further incident. Have all ground controllers immediately update any runway and approach changes on the IDS4 to reflect changes made by local control.




Synopsis: ARR Local Controller reported of a conflict due to confusion of runways in use at the time. Controller stated Information Display System 4 was not updated to show current configuration. Aircraft were landing on old and new configurations.