Small Aircraft
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 6
Situational Awareness; Confusion; Training / Qualification
ATC Issue All Types; Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Taxiway
Air Traffic Control Provided Assistance; Flight Crew Executed Go Around / Missed Approach
Airport; Human Factors
While working as CIC; I observed the following incident develop for Local Control; a position in which OJTI (On-the-Job Training Instructor) was being provided at the time of this event. Aircraft X made a short approach to Runway 31 and after appearing to roll past Taxiway Bravo; made a greater than 90 degree turn back to start exiting Bravo. Due to an airport reconstruction project; aircraft are proceeding onto Runway 31 at Bravo for departures and there was an aircraft holding short of Bravo waiting to depart. The Local Controller instructed the aircraft to turn right onto Taxiway Zulu; which is the opposite direction of the ramp; but the only way the arrival could fully exit the runway. Aircraft X did not understand the instruction and held on Bravo; which was not fully clear of the runway. I pointed that out to the Local Controller.The OJTI then intervened to send an aircraft; Aircraft Y; who was just inside a 1/4 mile final to go-around. Aircraft Y did not respond and the OJTI made repeated calls for them to go-around. On the third call; Aircraft Y acknowledged and started to go-around; by which time they had already crossed the runway threshold; though they did not touch down. An overflight did not occur due to Aircraft X holding just shot of Taxiway Zulu; which is still offset from the runway. I then had a Controller relieve the Local Controller and OJTI while also calling the Supervisor working downstairs to relieve me and cover the report as I was minutes away from the end of my shift. I consulted with the Supervisor if we should issue a brasher warning to Aircraft X; who I felt did not follow ATC instructions in exiting the runway. But; the Supervisor declined. The Supervisor then filled out the report as I was at the end of [the] shift.Our ATIS already mentions a fair bit of extra instructions for the unusual closure at Taxiway A. I question if there is more information that could be made available to pilots via other means that could go into more detail about the closer; expected routes; and the required read backs during the unusual set up.
PAO Tower Controller reported a runway incursion resulting in a go-around possibly due to airport construction.