Narrative:

I had small transport X at 70 on V510 sebound and was climbing small aircraft Y northwest on V510 to 80. Small aircraft Y was climbing slow and was just reaching 50 when I turned him 15 degree off the airway, 'vector for climb, opposite direction traffic, 12 O'clock and 10 mi.' small aircraft Y acknowledged and read back the heading of 280 degree. I thought about stopping small aircraft Y's climb at 60 but due to the convention we were having trouble coordination with chicago center so I wanted him level at 80 before making my handoff. I had sent 2 70's to south radar already and was about to send 2 more (all crossing) so started to coordination a plan of action with the south controller as he already had 4 crossing 70's and was about to get 2 more. When I noticed the situation, small aircraft Y was leaving 60 and was 5 mi away. He was also on the centerline of the airway. As I was about to issue evasive turns to both aircraft, a third aircraft came on the air with a PIREP. (After listening to the tape, the PIREP took approximately 18 seconds). By the time the PIREP was finished, the small aircraft Y was through 64 and was at 3 or less and 12 O'clock. I immediately issued evasive turns to both aircraft. Targets merged and I never saw the altitude readout. By this time I had told my supervisor (at the data position) I have an error, and he advised I had 500 ft at the time they merged. After they passed, I put them both back on course. Small aircraft Y advised it was a 'near miss'. Contributing factors: experience told me to level small aircraft Y at 60 but landline situation made me change. If south side radar would have needed help, he would have asked, or not taken my handoffs; yet I let my attention be diverted to his airspace. The PIREP got in the way. I feel if a pilot is going to make a long transmission, he should first ask if the controller is ready.

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Original NASA ASRS Text

Title: SMA Y HAD LTSS FROM SMT X. NMAC. SYS ERROR.

Narrative: I HAD SMT X AT 70 ON V510 SEBOUND AND WAS CLBING SMA Y NW ON V510 TO 80. SMA Y WAS CLBING SLOW AND WAS JUST REACHING 50 WHEN I TURNED HIM 15 DEG OFF THE AIRWAY, 'VECTOR FOR CLB, OPPOSITE DIRECTION TFC, 12 O'CLOCK AND 10 MI.' SMA Y ACKNOWLEDGED AND READ BACK THE HDG OF 280 DEG. I THOUGHT ABOUT STOPPING SMA Y'S CLB AT 60 BUT DUE TO THE CONVENTION WE WERE HAVING TROUBLE COORD WITH CHICAGO CENTER SO I WANTED HIM LEVEL AT 80 BEFORE MAKING MY HDOF. I HAD SENT 2 70'S TO S RADAR ALREADY AND WAS ABOUT TO SEND 2 MORE (ALL XING) SO STARTED TO COORD A PLAN OF ACTION WITH THE S CTLR AS HE ALREADY HAD 4 XING 70'S AND WAS ABOUT TO GET 2 MORE. WHEN I NOTICED THE SITUATION, SMA Y WAS LEAVING 60 AND WAS 5 MI AWAY. HE WAS ALSO ON THE CENTERLINE OF THE AIRWAY. AS I WAS ABOUT TO ISSUE EVASIVE TURNS TO BOTH ACFT, A THIRD ACFT CAME ON THE AIR WITH A PIREP. (AFTER LISTENING TO THE TAPE, THE PIREP TOOK APPROX 18 SECS). BY THE TIME THE PIREP WAS FINISHED, THE SMA Y WAS THROUGH 64 AND WAS AT 3 OR LESS AND 12 O'CLOCK. I IMMEDIATELY ISSUED EVASIVE TURNS TO BOTH ACFT. TARGETS MERGED AND I NEVER SAW THE ALT READOUT. BY THIS TIME I HAD TOLD MY SUPVR (AT THE DATA POS) I HAVE AN ERROR, AND HE ADVISED I HAD 500 FT AT THE TIME THEY MERGED. AFTER THEY PASSED, I PUT THEM BOTH BACK ON COURSE. SMA Y ADVISED IT WAS A 'NEAR MISS'. CONTRIBUTING FACTORS: EXPERIENCE TOLD ME TO LEVEL SMA Y AT 60 BUT LANDLINE SITUATION MADE ME CHANGE. IF S SIDE RADAR WOULD HAVE NEEDED HELP, HE WOULD HAVE ASKED, OR NOT TAKEN MY HDOFS; YET I LET MY ATTN BE DIVERTED TO HIS AIRSPACE. THE PIREP GOT IN THE WAY. I FEEL IF A PLT IS GOING TO MAKE A LONG XMISSION, HE SHOULD FIRST ASK IF THE CTLR IS READY.

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.