A C172 INSTRUCTOR PLT RPTED AN NMAC WITH A SIKORSKI HELI WHILE IN THE PATTERN AT SNA ARPT.

Narrative

MY STUDENT AND I WERE IN L CLOSED TFC FOR RWY 19 L AT SNA ARPT. WE HAD AN NMAC WITH A SIKORSKY HELI. WE HAD A STANDING REQUEST WITH THE TWR; FOR THE 'OPTION;' ALLOWING US TO DO TOUCH-AND-GOES; STOP-AND-GOES; MAKE LOW PASSES; ETC. MY STUDENT WAS WORKING ON HIGH LNDGS; BUT HAS MORE THAN 40 HRS OF FLT TIME; AND WAS COMPETENT AT FLYING THE PATTERN. ON CLBOUT; AFTER ONE LOW PASS; MY STUDENT WAS CLBING OUT AT OUR SCHOOL'S RECOMMENDED INITIAL BEST ANGLE OF CLB; AND WAS PASSING THROUGH APPROX 100 FT MSL; WHEN THE TWR INDICATED THAT THERE WAS A HELI DEPARTING; AND THAT WE SHOULD EXTEND OUR UPWIND. WE RESPONDED THAT WE WOULD EXTEND OUR UPWIND; BUT DID NOT ACKNOWLEDGE THE HELI TFC; AS NEITHER OF US HAD THAT TFC IN SIGHT. AT THIS POINT; IN MY MIND; I DID NOT THINK THAT THE HELI WAS A FACTOR; AS THIS TWR INSTRUCTION DID NOT CHANGE OUR CURRENT HDG; WHICH WAS APPROX 175 DEGS MAGNETIC. THIS DEP HDG COMPLIES WITH THE NORMALLY PUBLISHED 15 DEG TURN TO THE L; AT THE END OF RWY 19L AT JOHN WAYNE ARPT. AT ROUGHLY 250 FT MSL; MY STUDENT BEGAN TO SAY SOMETHING ABOUT A HELI; AND BEFORE HE COULD COMPLETE HIS SENTENCE; I SAW THE HELI ENTER MY FIELD OF VIEW ON MY STUDENT'S SIDE (FRONT L QUARTER); ASCENDING. I TOOK THE CTLS FROM THE STUDENT; AND QUICKLY TURNED TO THE R ABOUT 45 DEGS; WHILE CONTINUING OUR CLBOUT; AND SUCCESSFULLY EVADING THE TFC. AT THE CLOSEST POINT; I BELIEVE THE HELI WAS ABOUT 2 LIGHT ACFT LENGTHS AWAY; APPROX 60 FT AND VERT ABOUT 1/2 OF THAT; ROUGHLY 30 FT. THE VISIBILITY ON THAT DAY WAS 5 MI IN HAZE; WITH NO OTHER OBSTRUCTIONS TO VISION. THE VISIBILITY AT THESE DISTANCES WAS DEFINITELY NOT A FACTOR FOR EITHER ACFT'S AIRCREW. I DIDN'T THINK IT WAS PROBLEMATIC FOR THE TWR. MY IMPRESSION AT THE TIME WAS THAT THE HELI PLT NEVER SAW US. I WAS UNABLE TO ACCURATELY SEE THE TYPE OF HELI; OR MARKINGS; AS ITS TAIL WAS TOWARDS US. I LATER LEARNED ABOUT ITS MAKE AND THE TYPE OF DEP THAT IT WAS ON; WHICH WAS A L; CLBING 270 DEG DEP; OVER THE TOP OF THE ARPT. MY BELIEF IS THAT THE HELI WAS ISSUED A DEP CLRNC PREMATURELY; AS ANOTHER 10-15 SECONDS WOULD HAVE PLACED US WITHIN THE FIELD OF VIEW OF THE HELI PLT AND CLR OF A POTENTIAL CONFLICT. THE OTHER POSSIBILITY; IN MY MIND; WAS THAT THE CLRNC WAS ISSUED WHILE THE HELI'S FLT PATH WAS CLR. THEN; HE DELAYED HIS DEP; CREATING THE POTENTIAL CONFLICT; WHEREBY THE CLRNC SHOULD HAVE BEEN RETRACTED BY THE TWR. I REQUESTED A PHONE NUMBER; AND CONTACTED THE TWR TO DISCUSS THE INCIDENT AS SOON AS I WAS ON THE GND. I EXPRESSED MY FRUSTRATION WITH THE SIT AND MY DESIRE TO FIND A SAFE RESOLUTION TO THE PROB; SO THAT THE POTENTIAL FOR THIS SORT OF OCCURRENCE IS LIMITED IN THE FUTURE.