Narrative:

Aircraft X was a departure off of sheppard AFB heading to the washita MOA southwest of oklahoma city. Aircraft Y was leaving the washita MOA going back to sheppard AFB. Aircraft X was stopped at 16000 ft with transponder problems. Aircraft Y was at 17000 ft going back to sheppard. Aircraft Y began descending while almost on top of aircraft X. I quickly called sheppard to see if they were descending aircraft Y. They said, 'no, they were not talking to him yet. A few seconds later, they yelled they did have aircraft Y. I had previously advised sheppard that I would leave aircraft X at 16000 ft until past the aircraft Y flight. After pulling tapes, it was decided it was a pilot deviation as far as we could tell. Both flts had received the correct clrncs. There were 2 center sectors involved, plus sheppard approach. I never talked to aircraft Y because of a prearranged procedure where the okc-lo sector hands me the data block and I in turn, hand it off to sheppard. Aircraft X did see aircraft Y and asked for his call sign. Conflict alert went off, but the snitch patch never went off due to air carrier's transponder problems -- no mode C was displayed. Aircraft Y did climb back to 17000 ft, it was noticed. I am not sure if sheppard approach might have started down the aircraft Y flight too soon or not. They do have a lot of trainee ATC's and do make more mistakes because of this fact.

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Original NASA ASRS Text

Title: 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.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.