NMAC BTWN AN R22 AND R44 HELI IN A TRAINING AREA 3 MI NE OF DVT; AZ.

Narrative

ON THE MORNING OF MAR/TUE/04; AROUND XA00; I WAS CLRED INTO THE NE PRACTICE AREA BY PHOENIX (DEER VALLEY) TWR CTLR; ALONG WITH A LAW ENFORCEMENT HELI ACFT Y. AFTER ESTABLISHING WHERE ACFT Y WAS GOING TO OPERATE WITHIN THE PRACTICE AREA; WE MOVED E FOR SEPARATION. AS PART OF THE CLRNC; ATC INFORMED ME THAT ACFT Y WAS OPERATING IN THE PRACTICE AREA. AFTER FLYING AND SETTING UP AN APCH FOR A LNDG IN A CLR AREA IN THE DESERT; AN ACFT Z APPEARED AT ABOUT 25 FT FROM THE INTENDED LNDG SPOT. I TOOK THE CTLS FROM STUDENT; SAID SOME CHOICE WORDS ABOUT THE OTHER ACFT; AND BEGAN A GAR. WHILE INITIATING THE PWR RECOVERY; THE WIND BLEW ME CLOSER TOWARD THE OTHER R44 HELI PATH. THE OTHER HELI HAD A PROB WITH CTL BUT MANAGED TO MOVE OUT OF THE WAY OF MY DOWNWASH. I THEN CALLED DVT TWR AND ASKED CTLR HOW MANY HELIS WERE IN THE PRACTICE AREA. CTLR ADVISED 1 HELI AND THEN CALLED FOR ACFT Y TO RPT IN. I THEN ADVISED DVT TWR THERE WERE 3 HELIS IN THE NE PRACTICE AREA. BOTH HELIS WERE UNDAMAGED; BUT NEEDED TO TAKE EVASIVE ACTION TO AVOID A COLLISION. I THINK DVT TWR SHOULD HAVE BEEN DILIGENT IN KNOWING THE NUMBER OF HELIS.