Skyhawk 172/Cutlass 172
Air Traffic Control Fully Certified
Communication Breakdown
ATC Issue All Types; Conflict Ground Conflict; Critical; Ground Incursion Runway
Air Traffic Control Issued New Clearance; Flight Crew Took Evasive Action
Human Factors
Local Control split between two positions; Local North (Runway 9L) and Local South (Runway 9R). I was working Local Control North with Aircraft X in the local traffic pattern on short final. As I looked down to organize my strip bay; Aircraft X keyed up on my frequency and stated he was going around due to traffic on the runway. Local south controller had issued takeoff instructions to Aircraft Y who mistakenly called holding short of 9R. Aircraft Y was actually holding short of 9L and taxied onto the runway for takeoff roll. I advised Local South of the situation and Aircraft Y was allowed to continue takeoff roll and subsequently depart. Aircraft X was given instructions to fly northbound to rejoin the downwind for 9L and landed safely without incident. Recommend increased awareness and communications between aircraft and controllers alike.
Tower Controller clears aircraft for takeoff thinking the aircraft was at Runway 9R when it was at Runway 9L. When the aircraft started to depart; a landing aircraft went around.