HELI X NON ADHERENCE TO ATC INSTRUCTIONS HAD LTSS FROM ACR Y. PLTDEV. SYS ERROR.

Narrative

HELI X WAS N OF ZZZ; SBOUND TO STADIUM (NOT LIFEGUARD STATUS). HE CALLED S DEP RADAR. HE WAS NOT INSTRUCTED TO REMAIN OUTSIDE THE ARSA. HE WAS INSTRUCTED TO CALL N DEP RADAR (ME) AND GIVEN A TRANSPONDER CODE. HE CONTACTED ME. I IDENTED HIM (EVEN THOUGH HE WAS NOT ON THE CORRECT CODE; AND IT TOOK SEVERAL TRANSMISSIONS TO EXPLAIN IT TO HIM) 4 MI NW OF ZZZ ARPT. WE WERE DEPARTING RWYS 23L AND 23R. I GAVE HIM A HDG N OF ZZZ (100 DEGS) AND TOLD HIM TO CROSS THE APCH END OF RWY 23R (HIS ALT -- APPROX 1100 AGL). HE CROSSED THE DEP END OF RWY 23R AND AN ACR Y HAD TO TURN TO AVOID HIM. MY MISTAKE -- I HAD NOT TOLD THE TWR ABOUT HIM (IT WAS THEIR AIRSPACE) BECAUSE OF OVERFLT TFC AND INTRAFAC COORD WORKLOAD AND BECAUSE I TRUSTED HIM TO DO AS I HAD INSTRUCTED. HIS MISTAKE -- EVEN THOUGH HE WAS LEGAL UNTIL THE POINT HE DISREGARDED MY INSTRUCTIONS; HE DIDN'T SHOW MUCH SENSE IN FLYING THAT CLOSE TO THE ARPT AT THAT ALT. HE IS A LCL OPERATOR AND MUST HAVE SOME IDEA OF OUR OP (HE HAD TO KNOW HE WAS IN A TERRIBLE LOCATION); OR AT LEAST THE CORRECT FREQ. THIS IS NOT THE FIRST TIME; I AM TOLD; THAT WE HAVE HAD PROBLEMS WITH THE HELIS.