PLT TRNEE OF AN LTT ACFT FAILED TO STOP AND HOLD SHORT OF AN ACTIVE RWY RESULTING IN ANOTHER ACFT BEING SENT AROUND.

Narrative

INCIDENT OCCURRED DURING TRAINING IN PREPARATION FOR AN ATP/TYPE RATING CHK RIDE. AFTER COMPLETING AN ILS APCH TO RWY 36 WITH THE INTENTION OF CIRCLING TO LAND ON RWY 18; ATC CHANGED THE LNDG CLRNC TO RWY 21. THERE WAS LITTLE DIFFICULTY IN MODIFYING THE CIRCLE TO ACCOMMODATE THE CHANGE IN LNDG RWY. ON ROLLOUT THE TWR ADVISED US TO ROLL TO THE END; HOLD SHORT OF RWY 18 AND REMAIN WITH HIM. I WAS FLYING THE ACFT AND ACKNOWLEDGED THE HOLD SHORT INSTRUCTION. WE CONTINUED TAXIING TO THE RWY END AND BEGAN DISCUSSING THE NEXT TRAINING PROCS. INVOLVED IN THE DISCUSSION WITH THE INSTRUCTOR; UNFAMILIAR WITH THE ARPT LAYOUT; AND MOSTLY; NOT PAYING ATTN; I TAXIED ONTO THE DEP END OF THE ACTIVE RWY. A COMMUTER AIRLINER WAS ON SHORT FINAL AND THE TWR INSTRUCTED HIM TO GAR. THE TWR THEN CLRED US ACROSS THE RWY AND TO PARKING WITH A REQUEST TO CALL THE TWR AFTER SHUTDOWN. THE INSTRUCTOR PLT COMPLIED WITH THAT REQUEST AND THE INCIDENT WAS APPARENTLY ENDED. THIS INCIDENT COULD HAVE BEEN PREVENTED BY: MAKING ACFT CTL A PRIORITY AND AVOIDING THE TEMPTATION OF TRYING TO DO TOO MANY THINGS AT ONE TIME. HAVING THE TAXI CHART IN FRONT OF ME. MAINTAINING POSITIONAL AWARENESS.