Cessna Single Piston Undifferentiated or Other Model
Air Traffic Control Developmental
Communication Breakdown; Training / Qualification
ATC Issue All Types; Conflict Ground Conflict; Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Incursion Runway
Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented
Airport; Procedure; Human Factors
I was training on Local Control. Aircraft X landed; I told them to turn left on a taxiway and contact ground. Aircraft Y was cleared to land and on a short final for an intersecting runway. Ground Control asked for a crossing. I said hold short. Ground told Aircraft X to cross the runway. My trainer reacted quickly and yelled hold short to Ground Control. At this time Aircraft Y had touched down and there was no way to send him around. Ground quickly told Aircraft X to stop and hold short of the runway. Aircraft X continued his crossing until realizing he needed to get off the runway. He made a 180 degree turn back; to hold short of 21 at the taxiway.
A Tower Controller reported the Ground Controller allowed an aircraft to enter a runway at the same time another aircraft was landing.