SMT X HAD NMAC LTSS FROM SMT Y. SYS ERROR.

Narrative

IT WAS VERY EARLY ON A FOGGY LATE WINTER DAY. THE RWY CONFIGN WAS LNDG W; DEPARTING N. I HAD JUST ARRIVED IN THE TWR AND WAS WORKING ALL OF THE TWR POS COMBINED. DUE TO THE WX SOME OF THE CARGO HAULERS WERE STILL LEAVING. I DEPARTED SMT X OFF OF RWY 36. HIS RTE WAS TO JOIN V-81 (DEN 155 DEG RADIAL) S TO PUEBLO. HIS INITIAL ASSIGNED HDG WAS 040 DEGS (KEEPING WITHIN NOISE ABATEMENT CONSTRAINTS). HE SHOULD HAVE STAYED ON THAT HDG UNTIL AT LEAST 7500 FT MSL. HE WAS PUT ON THIS HDG TO BE SEPARATED FROM THE NEXT DEP; SMT Y WHO WAS ON A RWY HDG AFTER DEP TO EVENTUALLY JOIN THE DEN 335 DEG RADIAL. WHEN SMT X WAS OUT OF 6400 FT MSL THE DEP CTLR CALLED UP TO REQUEST AN EARLY TURN. I APPROVED THIS ASSUMING THE DEP CTLR WOULD TURN HIM R TO JOIN HIS REQUESTED RTE. INSTEAD THE DEP CTLR THOUGHT SMT X WAS ASSIGNED RWY HDG (WHICH IS NORMAL) AND TURNED SMT X L TO A HDG OF 190 DEGS. THE 040 DEG HDG WAS CLRLY WRITTEN ON THE FLT STRIP. WHEN DEP CTLR CALLED TO REQUEST THE TURN I REITERATED THE FACT THAT THE SMT X WAS ON A 040 DEG HDG. LATER HE SAID HE DIDN'T HEAR THAT PART OF THE COORD (WHICH THE TAPE RECORDING CLRLY DEMONSTRATED) NOR DID HE NOTICE THE 040 DEG RADIAL WRITTEN ON THE FLT PROGRESS STRIP. SMT X PASSED THE DEP FLT PATH AT AN ALT OF 1100 FT ABOVE THE DEP ACFT. AT THIS POINT NORMALLY ALT SEPARATION COULD BE DISCONTINUED BECAUSE THE FLT PATHS WERE DIVERGING. (7110.65G PARAGRAPH 5-73.) HOWEVER; SMT X CONTINUED HIS L TURN BACK TOWARDS THE ARPT ON A SEASTERLY HDG. THE DEP CTLR NOTICING THE PROB ISSUED TFC TO THE SMT Y THEN ATTEMPTED TO TURN THE SMT X TO A 270 DEG HDG. AT THIS POINT THE SMT X WAS HDG APPROX 160 DEGS. SMT X MADE A COMPLETE 360 DEG TURN AND ENDED UP HDG DUE N BEFORE FINALLY GETTING A TURN TO A HDG OF 090 DEGS TO GET SEPARATED FROM THE SMT Y. HE HAD COMPLETELY CIRCLED THE SMT Y FLT PATH. AN OPERROR WAS CALLED ON THE LCL CTLR BECAUSE I ALLOWED THE DEP TO TURN THE ACFT WITHOUT SPECIFYING A R TURN TOWARDS THE FILED RTE. NO DEV WAS CALLED ON THE SMT X FOR TURNING BEYOND THE 190 DEG HDG THAT WAS ISSUED. THE ACFT PASSED WITHIN A COUPLE HUNDRED FT OF EACH OTHER WHILE THE SMT X WAS ON THE SE HDG.