Narrative:

Mia ATC tower, east operation runways 9L, 9R and 12 active. 2 local controls, north and south. I was working cabin attendant coordination north (ccn). I received position relief briefing from lcn to open ccn position while it was busy, moderate to heavy traffic. The briefing was quick. During the brief I was led to believe that lcs had received releases for 2 departures from lcn. The departures being a northbound twin propeller and a sbound heavy jet. On an east operation lcs own runway 9R for arrs, but does not own any departure headings and must coordination for releases with lcn or ccn. I was under the impression that the releases had been coordination, when in fact they hadn't. After being on position 40 seconds, I called lcs to confirm that lcs was released on the traffic departing runway 12. At that time lcs said their releases were on a northbound propeller and a northbound heavy jet. I also wanted crossing clearance for 2 aircraft downfield runway 12. At that point I started scanning runway 12 to make sure it was clear and I didn't hear northbound heavy. Lcs rolled air carrier X, heading 090 maintain 50 off runway 9R. Lcn then rolled aircraft Y heading 090 maintain 50 off runway 9L. The 2 aircraft automatic acquired side by side 1 mi apart. Lcn, lcs or myself did not catch the mistake until departure control had established visual separation. An operational error was filed on me as ccn, as we had no form of separation off the airport.

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Original NASA ASRS Text

Title: MULTIPLE RWY OP PARALLEL RWYS ACR X HAD LTSS FROM ACR Y. SYS ERROR.

Narrative: MIA ATC TWR, E OP RWYS 9L, 9R AND 12 ACTIVE. 2 LCL CTLS, N AND S. I WAS WORKING CAB COORD N (CCN). I RECEIVED POS RELIEF BRIEFING FROM LCN TO OPEN CCN POS WHILE IT WAS BUSY, MODERATE TO HVY TFC. THE BRIEFING WAS QUICK. DURING THE BRIEF I WAS LED TO BELIEVE THAT LCS HAD RECEIVED RELEASES FOR 2 DEPS FROM LCN. THE DEPS BEING A NBOUND TWIN PROP AND A SBOUND HVY JET. ON AN E OP LCS OWN RWY 9R FOR ARRS, BUT DOES NOT OWN ANY DEP HDGS AND MUST COORD FOR RELEASES WITH LCN OR CCN. I WAS UNDER THE IMPRESSION THAT THE RELEASES HAD BEEN COORD, WHEN IN FACT THEY HADN'T. AFTER BEING ON POS 40 SECONDS, I CALLED LCS TO CONFIRM THAT LCS WAS RELEASED ON THE TFC DEPARTING RWY 12. AT THAT TIME LCS SAID THEIR RELEASES WERE ON A NBOUND PROP AND A NBOUND HVY JET. I ALSO WANTED XING CLRNC FOR 2 ACFT DOWNFIELD RWY 12. AT THAT POINT I STARTED SCANNING RWY 12 TO MAKE SURE IT WAS CLR AND I DIDN'T HEAR NBOUND HVY. LCS ROLLED ACR X, HDG 090 MAINTAIN 50 OFF RWY 9R. LCN THEN ROLLED ACFT Y HDG 090 MAINTAIN 50 OFF RWY 9L. THE 2 ACFT AUTO ACQUIRED SIDE BY SIDE 1 MI APART. LCN, LCS OR MYSELF DID NOT CATCH THE MISTAKE UNTIL DEP CTL HAD ESTABLISHED VISUAL SEPARATION. AN OPERROR WAS FILED ON ME AS CCN, AS WE HAD NO FORM OF SEPARATION OFF THE ARPT.

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.