MIL T38 DEPARTS TRAINING AIRSPACE AND CONFLICTS WITH ANOTHER MIL T38 ENRTE TO THE TRAINING AREA.

Narrative

ACFT X WAS A DEP OFF OF SHEPPARD AFB HEADING TO THE WASHITA MOA SW OF OKLAHOMA CITY. ACFT Y WAS LEAVING THE WASHITA MOA GOING BACK TO SHEPPARD AFB. ACFT X WAS STOPPED AT 16000 FT WITH XPONDER PROBS. ACFT Y WAS AT 17000 FT GOING BACK TO SHEPPARD. ACFT Y BEGAN DSNDING WHILE ALMOST ON TOP OF ACFT X. I QUICKLY CALLED SHEPPARD TO SEE IF THEY WERE DSNDING ACFT Y. THEY SAID; 'NO; THEY WERE NOT TALKING TO HIM YET. A FEW SECONDS LATER; THEY YELLED THEY DID HAVE ACFT Y. I HAD PREVIOUSLY ADVISED SHEPPARD THAT I WOULD LEAVE ACFT X AT 16000 FT UNTIL PAST THE ACFT Y FLT. AFTER PULLING TAPES; IT WAS DECIDED IT WAS A PLTDEV AS FAR AS WE COULD TELL. BOTH FLTS HAD RECEIVED THE CORRECT CLRNCS. THERE WERE 2 CTR SECTORS INVOLVED; PLUS SHEPPARD APCH. I NEVER TALKED TO ACFT Y BECAUSE OF A PREARRANGED PROC WHERE THE OKC-LO SECTOR HANDS ME THE DATA BLOCK AND I IN TURN; HAND IT OFF TO SHEPPARD. ACFT X DID SEE ACFT Y AND ASKED FOR HIS CALL SIGN. CONFLICT ALERT WENT OFF; BUT THE SNITCH PATCH NEVER WENT OFF DUE TO ACR'S XPONDER PROBS -- NO MODE C WAS DISPLAYED. ACFT Y DID CLB BACK TO 17000 FT; IT WAS NOTICED. I AM NOT SURE IF SHEPPARD APCH MIGHT HAVE STARTED DOWN THE ACFT Y FLT TOO SOON OR NOT. THEY DO HAVE A LOT OF TRAINEE ATC'S AND DO MAKE MORE MISTAKES BECAUSE OF THIS FACT.