Date: 201706
Local time of day: 1201-1800
Location: ISP.Tower, NY
Flight conditions: VMC
Light: Daylight
Aircraft: Skyhawk 172/Cutlass 172
Operator: Personal
Operating under: Part 91
Mission: Passenger
Flight phase: Taxi
Airspace: Class C ISP
ATC / advisory: Tower ISP
Second aircraft: PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Reporter organization: Government
Reporter function: Ground
Reporter qualification: Air Traffic Control Developmental
Human factors: Situational Awareness
Second reporter function: Single Pilot
Anomaly: Conflict Ground Conflict; Critical; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Incursion Runway
Detector: Person Flight Crew; Person Air Traffic Control
When detected: Taxi
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Separated Traffic; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action; Flight Crew Became Reoriented
Contributing factors: Airport; Human Factors; Procedure; Chart Or Publication
Primary problem: Human Factors

Narrative: Aircraft X landed on Runway 33R and were assigned to taxi left on Runway 24 and hold short Runway 33L. He acknowledged with hold short instruction. There was a PA28 Aircraft Y short final for Runway 33L. During Aircraft Y touching down; Aircraft X was still short of Runway 33L. When Aircraft Y was rolling out; Aircraft X crossed the hold short line of Runway 33L and held approximately 20 feet off the hold short line. Then the local control told Aircraft Y to exit taxiway to avoid the conflict. When he couldn't exit off and passed the Cessna by approximately 20 feet wing to nose. Aircraft Y had to curve around to pass the Cessna. After he was handed off to me officially crossing Runway 33L and turned on taxiway B. As I was a ground controller; I assigned him taxi instruction and gave him a brasher warning 'possible pilot deviation; contact tower' he took the number and taxied to the ramp. [I recommend] the pilots get more training about ground symbols and marking.


Second narrative: The event just happened [this] afternoon after I have landed. I was carrying 2 passengers on the board for introductory flight and I decided to return back to home base. There were 2 active runways which used parallel to each other during a landing. The one was 33L; and the other was 33R. The controller cleared me to make landing over the 33R which is a shorter runway than the other. After I have touched down; I have started rolling over the runway to vacate Runway 33R. I was just passed one of the taxiway Echo and continued the taxi until approach end of the runway. When I came in the end of the runway; the controller gave me another instruction which is to make' left turn on Runway 24 and hold and short for Runway 33L'. I repeated instruction. I was very sure and clearly understood the instruction. I was going to stop and wait before crossing the Runway 33L to give a way another traffic. As soon as I have turn over the Runway 24; I could not see holding short line and getting closer active runway. After that; the one of the aircraft was approaching us from left side of the runway. As soon as I have seen that I made a sudden brake to stop the aircraft. Meanwhile the controller was warning us to stop right before entering the active runway. In this situation I was totally wrong about looking for the hold short line instead of watching the other traffic on the runway.


Synopsis: A Ground Controller and local pilot reported a runway incursion between a landing aircraft and a taxiing aircraft.