Date: 201911
Local time of day: 0601-1200
Location: ISM.Tower, FL
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: Small Aircraft
Operator: FBO
Operating under: Part 91
Flight plan: None
Mission: Training
Flight phase: Takeoff / Launch
Airspace: Class D ISM
ATC / advisory: Tower ISM
Second aircraft: Small Aircraft
Reporter organization: FBO
Reporter function: Pilot Not Flying; Instructor
Reporter qualification: Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument
Human factors: Communication Breakdown; Other / Unknown
Anomaly: ATC Issue All Types; Conflict Ground Conflict; Critical
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action
Contributing factors: Procedure; Airport; Human Factors
Primary problem: Airport

Narrative: I was flight instructing in our aircraft from the backseat (my student was at the controls in the front seat). We were conducting crosswind takeoff techniques and had been cleared touch and go Runway 06 at ISM. Because the winds were coming approximately 080 at 12 kts; proper technique is to get on the upwind (right) wheel with the tailwheel up; and maintain directional control as you roll down the runway. My student was on the right wheel which in turn kept the right wing lower; blocking both his and my view from taxiway Alpha coming up on our right. We had just crossed over the Runway 15-33/6-24 intersection at the center of ISM and my student yelled out and applied full power; accelerated to rotation speed then banked to the right as he got about 10 feet in the air. This all was in a span of about 3 seconds. It was at this time that Aircraft Y came into my view from the backseat; directly to our left; crossing active Runway 06 south to north on taxiway Alpha. We were lucky to be close to flying airspeed because the immediate application of power resulted in us becoming air born quick enough to bank to the right and avoid Aircraft Y. We avoided striking the Aircraft Y by approximately 15 feet laterally and were roughly 2 feet higher than their vertical stabilizer. I did not attempt to take the controls from or manipulate his inputs because his actions were not unsafe to us and I knew he had seen something in the front seat that I could not see yet in the back (bird avoidance is very common here and I thought maybe that's what he was doing). I chose not to take the controls because he was not close to stall and did not want to make the situation (one that I didn't know the nature of yet) worse. Had I taken the controls and steered us back onto the runway; we would have either struck Aircraft Y with our front fuselage or landing gear. My student's actions were correct and saved ours and her life. My student was a high time airline pilot and was training for his tailwheel endorsement. We continued to do touch and go's for about 30 more minutes and were informed by the tower that we needed to call them upon our return to landing; which we did and my student provided his contact information. What appears to have caused this situation was the pilot of Aircraft Y not following taxi instructions to hold short Runway 06 on taxiway Alpha; as we had been cleared touch and go. We are an airport with a lot of flight schools so mistakes happen; but installment of a Hotspot on the airport diagram for stressing importance of not only receiving clearance to cross all runways (active and non-active); but also to visually scan the approach end of the runway prior to crossing; as is taught to us during our PPL phase of training.




Synopsis: Small aircraft instructor reported an NMAC with ground traffic crossing runway.