Medium Large Transport
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 19.7
Communication Breakdown
Conflict Ground Conflict; Critical; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Runway; Ground Incursion Taxiway
Air Traffic Control Issued New Clearance; Flight Crew Took Evasive Action
Human Factors; Airport
Aircraft X exited runway 28 Left at Tango and said forty for the gate. After clarifying forty minutes for the gate or forty past the hour; it was about twelve minutes to wait; I gave them taxi via B hold short of Q on their right hand side (runway exit). When I looked at Aircraft Y rolling out on Runway 28 Left to exit Q; while giving a pushback clearance to another aircraft at gate XX; Aircraft X was right in the middle of the intersection; and Aircraft Y had to make an evasive maneuver to continue back on Runway 28 L to the next exit. I told Aircraft X they were supposed to hold short of Q. They were then given B to the ramp as I no longer had a way to hold them with A blocked by pushback aircraft and taxiing aircraft all off of their left. Pilot conformance with instructions would have helped both of us as I hate to send them all of the way back to the ramp if I can stage the aircraft for a pushback far enough to allow them in; which eventually occurred. It just took them deeper in towards the ramp and a turn around. If there seems to be a hint of unfamiliarity; I try to help the pilots out to make sure we are on the same page. I did not get that during this event.
SFO Tower Controller reported a Medium Large Transport aircraft had a taxiway incursion resulting in a Large Transport aircraft taking evasive action.