Narrative:

I was vectoring small transport X inbound, IFR, for an ILS approach. Local control called me on override requesting a SVFR release for small aircraft Y northbound to 1a0. 1a0 is a VFR airport approximately 8 mi north of cha airport, west of the arrival/departure path for runway 20, inside the west sector airspace. I asked if the small aircraft Y was immediately ready to depart and was told yes. I released the aircraft, anticipating a west turnout which is standard. I widened small transport X's pattern vectors, anticipating the wbound course of small aircraft Y and the proximity of 1a0 to the arrival course. When small aircraft Y departed and contacted me, I was initially unable to establish radar identify. I determined that the aircraft was in a left turn to 1a0 which is nonstandard. Due to the aircraft's proximity to the radar antenna (which is on the airport) I was unable to establish radar contact until the aircraft was 1/2 mi east of the airport abeam and paralleling the runway on a 020 degree heading. At this time I instructed the aircraft to advise me prior to climbing above 25 and indicated such on the strip. At this time, I anticipated ensuring altitude sep by having small aircraft Y pass above small transport X. The error was human. It occurred when I looked at the strip on small aircraft Y and erroneously concluded that he was level at 25. The aircraft did not have mode C. I vectored small aircraft Y across the approach path in front of small transport X, and course divergence was established; but not before the aircraft were within 1 mi and 100' of each other. When I realized that the aircraft was not at 25, and that I did not have standard sep, I issued an evasive turn to small transport X, who reported the traffic in sight. Possible contributing factors: no standard SVFR procedures locally. Aircraft not issued heading to fly by local control. Lack of radar identify. Coordination confusion between local control and radar. Coordination between east/west radar when aircraft turned into east airspace. Other aircraft calling on frequency, possibly diverting attention. Human performance considerations: 3RD day back after nine days off. 1ST hour of 8 am shift after 2-10 pm shift previous day. No matter how many contributing factors were involved, the error still rests with me. I read 25 on the strip, somehow got it in my head that the aircraft was level at that altitude and issued my instructions with that in mind. In the time it took me to realize that that was not the case, the operation error had occurred. To prevent a recurrence: establish specific coordination procedures for SVFR departures reference intended headings, control sectors. Read and reread strips, use climbing or descending arrows on strips: especially when aircraft do not have mode C.

Related reports:

Google
 

Original NASA ASRS Text

Title: CTLR VECTORED CLIMBING SVFR DEP THROUGH THE PATH OF INBOUND IFR WITH NO ALT SEPARATION, RESULTING IN LESS THAN STANDARD SEPARATION.

Narrative: I WAS VECTORING SMT X INBND, IFR, FOR AN ILS APCH. LCL CTL CALLED ME ON OVERRIDE REQUESTING A SVFR RELEASE FOR SMA Y NBOUND TO 1A0. 1A0 IS A VFR ARPT APPROX 8 MI N OF CHA ARPT, W OF THE ARR/DEP PATH FOR RWY 20, INSIDE THE W SECTOR AIRSPACE. I ASKED IF THE SMA Y WAS IMMEDIATELY READY TO DEPART AND WAS TOLD YES. I RELEASED THE ACFT, ANTICIPATING A W TURNOUT WHICH IS STANDARD. I WIDENED SMT X'S PATTERN VECTORS, ANTICIPATING THE WBOUND COURSE OF SMA Y AND THE PROX OF 1A0 TO THE ARR COURSE. WHEN SMA Y DEPARTED AND CONTACTED ME, I WAS INITIALLY UNABLE TO ESTABLISH RADAR IDENT. I DETERMINED THAT THE ACFT WAS IN A LEFT TURN TO 1A0 WHICH IS NONSTANDARD. DUE TO THE ACFT'S PROX TO THE RADAR ANTENNA (WHICH IS ON THE ARPT) I WAS UNABLE TO ESTABLISH RADAR CONTACT UNTIL THE ACFT WAS 1/2 MI E OF THE ARPT ABEAM AND PARALLELING THE RWY ON A 020 DEG HDG. AT THIS TIME I INSTRUCTED THE ACFT TO ADVISE ME PRIOR TO CLBING ABOVE 25 AND INDICATED SUCH ON THE STRIP. AT THIS TIME, I ANTICIPATED ENSURING ALT SEP BY HAVING SMA Y PASS ABOVE SMT X. THE ERROR WAS HUMAN. IT OCCURRED WHEN I LOOKED AT THE STRIP ON SMA Y AND ERRONEOUSLY CONCLUDED THAT HE WAS LEVEL AT 25. THE ACFT DID NOT HAVE MODE C. I VECTORED SMA Y ACROSS THE APCH PATH IN FRONT OF SMT X, AND COURSE DIVERGENCE WAS ESTABLISHED; BUT NOT BEFORE THE ACFT WERE WITHIN 1 MI AND 100' OF EACH OTHER. WHEN I REALIZED THAT THE ACFT WAS NOT AT 25, AND THAT I DID NOT HAVE STANDARD SEP, I ISSUED AN EVASIVE TURN TO SMT X, WHO RPTED THE TFC IN SIGHT. POSSIBLE CONTRIBUTING FACTORS: NO STANDARD SVFR PROCS LOCALLY. ACFT NOT ISSUED HDG TO FLY BY LC. LACK OF RADAR IDENT. COORD CONFUSION BTWN LC AND RADAR. COORD BTWN E/W RADAR WHEN ACFT TURNED INTO E AIRSPACE. OTHER ACFT CALLING ON FREQ, POSSIBLY DIVERTING ATTN. HUMAN PERFORMANCE CONSIDERATIONS: 3RD DAY BACK AFTER NINE DAYS OFF. 1ST HOUR OF 8 AM SHIFT AFTER 2-10 PM SHIFT PREVIOUS DAY. NO MATTER HOW MANY CONTRIBUTING FACTORS WERE INVOLVED, THE ERROR STILL RESTS WITH ME. I READ 25 ON THE STRIP, SOMEHOW GOT IT IN MY HEAD THAT THE ACFT WAS LEVEL AT THAT ALT AND ISSUED MY INSTRUCTIONS WITH THAT IN MIND. IN THE TIME IT TOOK ME TO REALIZE THAT THAT WAS NOT THE CASE, THE OP ERROR HAD OCCURRED. TO PREVENT A RECURRENCE: ESTABLISH SPECIFIC COORD PROCS FOR SVFR DEPS REFERENCE INTENDED HDGS, CONTROL SECTORS. READ AND REREAD STRIPS, USE CLBING OR DSNDING ARROWS ON STRIPS: ESPECIALLY WHEN ACFT DO NOT HAVE MODE C.

Data retrieved from NASA's ASRS site as of August 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.