Aircoupe A2
Air Traffic Control Fully Certified
ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Incursion Runway
General None Reported / Taken
Human Factors; Procedure
We were running Runway 6 operations. When we are on Runway 6 our taxi routes get quite complex; Runway 18R is used as a taxiway when on Runway 6. A group of 10 planes had come in earlier in the day and they were all leaving at the time of the incident. Grumman called up to taxi out and was given the taxi instructions; taxi via Echo; Runway 18R; and Hotel; Cross Runway 18L. I believe I provided him with progressive taxi instructions as he was taxiing. Air Coupe called up right after him and was given the same taxi instructions. Air Coupe was also instructed to follow the Grumman and reported him in sight. Air Coupe was taxiing on Runway 18R as expected and was approaching his turn onto Hotel which runs adjacent to Runway 6. I was eating some food at the time and looked down to take a bite of food and that's when the Local Controller said he missed his turn and was going out onto the runway. The Local Controller had just cleared Grumman for takeoff and canceled his takeoff clearance. I instructed Air Coupe to hold position and then informed him that he missed Taxiway Hotel and had taxied out on to the runway. I then instructed him to make a 180; turn left on Taxiway Hotel; advised him of a possible pilot deviation and to call the Tower. After listening to the recorded transmissions between Air Coupe and myself it is apparent that he did not readback the taxi instructions correctly and I failed to hear the readback and correct him. Knowing that Runway 6 operations are tricky when it comes to taxiing; I should not have relied on the pilot to follow the proceeding airplane. I believe that by the pilot agreeing to follow the proceeding airplane it allowed me to relax and miss errors in the readback.
Ground Controller taxiing multiple aircraft to the runway with a 'follow the preceding aircraft' type clearance observed one of the aircraft entering the runway after the preceding departure.