Not very similar call signs on separate frequencys nearly cause a conflict.

Attributes
ACN	582432
Time
Date	200302
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	navaid : hmv.vortac
State Reference	TN
Altitude	msl single value : 1400
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : ztl.artcc
Operator	common carrier : air carrier
Make Model Name	Regional Jet CL65, Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude climbout : vacating altitude
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : ztl.artcc
Operator	common carrier : air carrier
Make Model Name	Regional Jet CL65, Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : vacating altitude climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 21 controller time certified in position1 : 10
ASRS Report	582432
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	non adherence : required legal separation non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance controller : issued advisory
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

I was working R45/46 combined. 1 person sector. Air carrier X roa-odf macey 2 atl was on a vector for traffic on frequency 132.9. Air carrier Y was on frequency 127.85. Air carrier Y tri-sot-odf macey 2 atl was also on a vector for traffic. Cleared air carrier X direct odf. Air carrier Y answered on 127.85. Fortunately, I caught it. He would have turned right into his traffic (head-on descending into tri/bristol, tn). I still don't see the call signs as being similar. However, when no one answered on 127.85 (the other aircraft air carrier X was on 132.9) he may have assumed I was talking to him.

Original NASA ASRS Text

Title: NOT VERY SIMILAR CALL SIGNS ON SEPARATE FREQS NEARLY CAUSE A CONFLICT.

Narrative: I WAS WORKING R45/46 COMBINED. 1 PERSON SECTOR. ACR X ROA-ODF MACEY 2 ATL WAS ON A VECTOR FOR TFC ON FREQ 132.9. ACR Y WAS ON FREQ 127.85. ACR Y TRI-SOT-ODF MACEY 2 ATL WAS ALSO ON A VECTOR FOR TFC. CLRED ACR X DIRECT ODF. ACR Y ANSWERED ON 127.85. FORTUNATELY, I CAUGHT IT. HE WOULD HAVE TURNED RIGHT INTO HIS TFC (HEAD-ON DSNDING INTO TRI/BRISTOL, TN). I STILL DON'T SEE THE CALL SIGNS AS BEING SIMILAR. HOWEVER, WHEN NO ONE ANSWERED ON 127.85 (THE OTHER ACFT ACR X WAS ON 132.9) HE MAY HAVE ASSUMED I WAS TALKING TO HIM.

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.