Narrative:

An AC69, an arrival to eye, was inbound from the southeast of indianapolis. A C550, an arrival to ind, was also inbound from the southeast. An E145 was inbound to ind from the northeast of indianapolis. C550 was in the arrival gate to the ind area. AC69 was paralleling his course outside of the area. I attempted to hand off AC69 to the controller working the airspace beneath me. He did not take the handoff due to traffic volume and the fact the aircraft was in a 'bad' position to continue his descent. I vectored AC69 into the arrival ara to start his descent, and then assigned him 8000 ft to stay above C550 and also the E145, both assigned 7000 ft. As he entered the arrival area, I sent him direct to brickyard VORTAC (vhp), which would keep him nwbound and ahead of E145. Departure east (or dre, the controller owning airspace beneath me) advised he was ready for the aircraft (AC69), and I descended him to 7000 ft, continued to project his course ahead of E145, and switched him to the dre. Knowing I had an 'out' if the aircraft stayed on his course, I watched it until I heard the dre controller assign him 6000 ft. I still projected courses to miss. I did not hear the dre controller turn the aircraft to the north (360 degrees) as I answered the landline pertaining to another aircraft in a corner of my airspace. I went to tell dre about that landline call, and he pointed out E145 and AC69 on conflicting courses both at 7000 ft. I turned E145 90 degrees left and pointed out the traffic as the dre controller expedited his descent and turned him back to the northwest. Separation was lost, and the error called. AC69 was in a bad place from the start. I should have insisted to be put in the arrival gate in-trail of the ind lander (C550), since the aircraft's performance in the terminal environment are similar, and the destinations only 5 mi apart. Before switching AC69, I should have assigned him an altitude below E145 and kept them before switching him. Trusting the dre controller, I didn't think twice about that decision. As a secondary plan, I could've taken the AC69 to 7000 ft, and kept E145 at 8000 ft, but I initially intended on getting E145 below AC69 and felt he could safely get below E145 after hearing the 6000 ft descent clearance. After all went bad, there was time to avoid the conflict. I could've issued an expedited climb to E145 to quickly gain vertical separation. Conclusions: keep aircraft on your frequency until separation is established. Keep other facilities in line by making them follow procedures established. Even though I was paying attention to the situation, I should've seen AC69 make his turn to the north and done something about it after everything had started to piece itself together. Had I known AC69 was on a northbound heading, I would've made E145 evasively move to the west of north, as tracks were very close as we were establishing proper vertical separation.

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Original NASA ASRS Text

Title: INADEQUATE COORD RESULTED IN A LOSS OF SEPARATION BTWN AN E145 ACR AND AC69 HANDED OFF WITH CONFLICTING COURSES.

Narrative: AN AC69, AN ARR TO EYE, WAS INBOUND FROM THE SE OF INDIANAPOLIS. A C550, AN ARR TO IND, WAS ALSO INBOUND FROM THE SE. AN E145 WAS INBOUND TO IND FROM THE NE OF INDIANAPOLIS. C550 WAS IN THE ARR GATE TO THE IND AREA. AC69 WAS PARALLELING HIS COURSE OUTSIDE OF THE AREA. I ATTEMPTED TO HAND OFF AC69 TO THE CTLR WORKING THE AIRSPACE BENEATH ME. HE DID NOT TAKE THE HDOF DUE TO TFC VOLUME AND THE FACT THE ACFT WAS IN A 'BAD' POS TO CONTINUE HIS DSCNT. I VECTORED AC69 INTO THE ARR ARA TO START HIS DSCNT, AND THEN ASSIGNED HIM 8000 FT TO STAY ABOVE C550 AND ALSO THE E145, BOTH ASSIGNED 7000 FT. AS HE ENTERED THE ARR AREA, I SENT HIM DIRECT TO BRICKYARD VORTAC (VHP), WHICH WOULD KEEP HIM NWBOUND AND AHEAD OF E145. DEP E (OR DRE, THE CTLR OWNING AIRSPACE BENEATH ME) ADVISED HE WAS READY FOR THE ACFT (AC69), AND I DSNDED HIM TO 7000 FT, CONTINUED TO PROJECT HIS COURSE AHEAD OF E145, AND SWITCHED HIM TO THE DRE. KNOWING I HAD AN 'OUT' IF THE ACFT STAYED ON HIS COURSE, I WATCHED IT UNTIL I HEARD THE DRE CTLR ASSIGN HIM 6000 FT. I STILL PROJECTED COURSES TO MISS. I DID NOT HEAR THE DRE CTLR TURN THE ACFT TO THE N (360 DEGS) AS I ANSWERED THE LANDLINE PERTAINING TO ANOTHER ACFT IN A CORNER OF MY AIRSPACE. I WENT TO TELL DRE ABOUT THAT LANDLINE CALL, AND HE POINTED OUT E145 AND AC69 ON CONFLICTING COURSES BOTH AT 7000 FT. I TURNED E145 90 DEGS L AND POINTED OUT THE TFC AS THE DRE CTLR EXPEDITED HIS DSCNT AND TURNED HIM BACK TO THE NW. SEPARATION WAS LOST, AND THE ERROR CALLED. AC69 WAS IN A BAD PLACE FROM THE START. I SHOULD HAVE INSISTED TO BE PUT IN THE ARR GATE IN-TRAIL OF THE IND LANDER (C550), SINCE THE ACFT'S PERFORMANCE IN THE TERMINAL ENVIRONMENT ARE SIMILAR, AND THE DESTS ONLY 5 MI APART. BEFORE SWITCHING AC69, I SHOULD HAVE ASSIGNED HIM AN ALT BELOW E145 AND KEPT THEM BEFORE SWITCHING HIM. TRUSTING THE DRE CTLR, I DIDN'T THINK TWICE ABOUT THAT DECISION. AS A SECONDARY PLAN, I COULD'VE TAKEN THE AC69 TO 7000 FT, AND KEPT E145 AT 8000 FT, BUT I INITIALLY INTENDED ON GETTING E145 BELOW AC69 AND FELT HE COULD SAFELY GET BELOW E145 AFTER HEARING THE 6000 FT DSCNT CLRNC. AFTER ALL WENT BAD, THERE WAS TIME TO AVOID THE CONFLICT. I COULD'VE ISSUED AN EXPEDITED CLB TO E145 TO QUICKLY GAIN VERT SEPARATION. CONCLUSIONS: KEEP ACFT ON YOUR FREQ UNTIL SEPARATION IS ESTABLISHED. KEEP OTHER FACILITIES IN LINE BY MAKING THEM FOLLOW PROCS ESTABLISHED. EVEN THOUGH I WAS PAYING ATTN TO THE SIT, I SHOULD'VE SEEN AC69 MAKE HIS TURN TO THE N AND DONE SOMETHING ABOUT IT AFTER EVERYTHING HAD STARTED TO PIECE ITSELF TOGETHER. HAD I KNOWN AC69 WAS ON A NBOUND HDG, I WOULD'VE MADE E145 EVASIVELY MOVE TO THE W OF N, AS TRACKS WERE VERY CLOSE AS WE WERE ESTABLISHING PROPER VERT SEPARATION.

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.