Date: 202009
Local time of day: 0001-0600
Location: ZZZ.Tower, US
Flight conditions: VMC
Light: Daylight
Aircraft: Challenger CL600
Operator: Government
Operating under: Part 91
Flight plan: VFR
Mission: Other Flight Check
Flight phase: Descent
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Second aircraft: PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Reporter organization: Government
Reporter function: Local
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Confusion; Workload; Situational Awareness; Distraction; Time Pressure
Anomaly: ATC Issue All Types; Conflict NMAC; Conflict Airborne Conflict; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Separated Traffic; Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; General Flight Cancelled / Delayed
Contributing factors: Human Factors; Procedure; Airspace Structure; Company Policy
Primary problem: Procedure

Narrative: I was working Local Control which manages the class D during north flow operations. Aircraft X had been doing air work at an adjacent airport which is about 8 to 9 miles west of this airport. Aircraft Y was inbound on the ILS. Aircraft Z and Aircraft A were inbound from the southwest. Approach called for a point out to Flight Data/Clearance delivery on Aircraft X and when asked what he was going to do we were told he was going back towards the adjacent airport. Aircraft X entered from the southwest and made maneuvers about 2 to 3 southwest at 2;300 feet and then turned southeast directly overflying Aircraft Y on the ILS by 400 feet. Aircraft Y was issued traffic alerts and broken off the approach to a 090 heading. This put them in conflict with Aircraft B; inbound from the southeast. Another traffic alert was given to Aircraft Y for Aircraft B. Just before Aircraft Y was broken off the ILS approach; Aircraft Z a VFR inbound from the southwest was issued a traffic alert since Aircraft X initially turned opposite direction to them. Aircraft A VFR from the southwest also had to be diverted to the east prior to Aircraft Y being broken off the approach because Aircraft X's intentions were unpredictable and not as described. When asked why flight check was turning east (right instead of left) toward our traffic we were told by approach that 'it is what it is.'Flight Check operations are a high risk to anyone else operating in the area. When they arrive their intentions are incredibly vague other than what they are checking. They often seem to just do whatever they want and let you know as they are doing it. From a local standpoint I think that flight check needs to be a lot more clear of their exact intentions) while operating in the vicinity. VFR arrivals need to be rerouted or placed in holding by approach to a different quadrant other than the one that Flight Check is operating in. This is not the first close call Flight Check has caused over the past few years.




Synopsis: A Tower Local Controller accepted a point out of a Flight Check aircraft which did not maneuver as expected causing conflicts with traffic on the final approach course.