MIL ACFT UNAUTH AIRSPACE ENTRY OPERATING IN PCA WITHOUT CLRNC. PLTDEV.

Narrative

I OBSERVED AN UNKNOWN TARGET NEAR BIRMINGHAM; AL; SHOWING FL517; AND WATCHED THE SUSPECT ACFT TRACK SEBOUND FOR APPROX 3 MINS. MY SECTOR IS FROM FL350 TO UPPER LIMIT OF PCA; FL600. I HAD A MIL FLT OF 2 FIGHTERS; CALL SIGN 'X' NEARBY; AND ASKED THE FLT LEADER IF HE COULD SEE A CONTRAIL AT THIS POS. HE REPLIED THAT HE COULD SEE A CONTRAIL; AND HAD INTERMITTENT RADAR CONTACT; SHOWING FL500. MY ASSOCIATE CTLR AND I THEN NOTICED NUMEROUS OTHER SUSPECT TARGETS IN OUR AIRSPACE; AT VARIOUS ALTS; AS LOW AS FL443; FOR APPROX 1 HR; UNTIL I WAS RELIEVED FOR A BREAK. MY RELIEF ALSO NOTICED THE SAME TYPE OF UNKNOWN TARGETS SEVERAL TIMES ON HIS WATCH. I ASKED MY SUPVR ABOUT THIS; AND WAS TOLD HE KNEW NOTHING. I HAVE FREQUENTLY OBSERVED SUSPECTED MIL ACFT SQUAWK IDENT ONLY ONCE; WITH UNKNOWN CODE ON XPONDER AT THIS SECTOR BUT THIS IS THE FIRST TIME THEY HAVE CONTINUED TO DISPLAY CODE MORE THAN 1 OR 2 'HITS;' OR 6-12 SECONDS. I ASKED THE MIL FLT 'X' IF THE TARGET SEEMED TO BE THE ACFT THAT HAS BEEN MENTIONED SO MUCH RECENTLY IN 'AEROSPACE WEEKLY AND SPACE DIGEST' BUT HE REPLIED 'MUST BE ELVIS.' IF IT WAS; WOULD THE MIL ADMIT IT?