Narrative:

On 3/91, I was working two aircraft southbound on V97, both landing at aby approximately 20 mi south of my airspace boundary. The lead aircraft was an small aircraft assigned 5000'. It was being overtaken by an light transport initially assigned 9000' and then 6000'. I issued the light transport a 10 degree right turn to maintain lateral sep with the small aircraft and then descended the light transport to 4000'. I observed 3 mi minimum sep at all times and xferred control and communication to jacksonville center (aby sector) when the light transport leveled at 4000'. Shortly thereafter, my watch supervisor received a call from atlanta center who said jacksonville center's 'snitch' had gone off and that separation between the two aircraft had dwindled to 2.8 mi lateral and 100' vertical. I have no computer to tell me what sep I have to the nearest tenth of a mi. I have to eyeball it which is what I did. What has happened because of the 'snitch' is that airspace efficiency had been significantly reduced. Controllers (especially in the ctrs) have greatly increased minimum sep standards so as to preclude any chance of setting off the snitch alarms. Why doesn't the system alert the controller to a potential loss of sep instead of telling him after the fact that he has had an operational error?

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Original NASA ASRS Text

Title: TERMINAL DEP CTLR VECTORED A FASTER ACFT AROUND A SLOWER ACFT WHICH RESULTED IN LESS THAN STANDARD SEPARATION.

Narrative: ON 3/91, I WAS WORKING TWO ACFT SBND ON V97, BOTH LNDG AT ABY APPROX 20 MI S OF MY AIRSPACE BOUNDARY. THE LEAD ACFT WAS AN SMA ASSIGNED 5000'. IT WAS BEING OVERTAKEN BY AN LTT INITIALLY ASSIGNED 9000' AND THEN 6000'. I ISSUED THE LTT A 10 DEG R TURN TO MAINTAIN LATERAL SEP WITH THE SMA AND THEN DSNDED THE LTT TO 4000'. I OBSERVED 3 MI MINIMUM SEP AT ALL TIMES AND XFERRED CTL AND COM TO JACKSONVILLE CTR (ABY SECTOR) WHEN THE LTT LEVELED AT 4000'. SHORTLY THEREAFTER, MY WATCH SUPVR RECEIVED A CALL FROM ATLANTA CTR WHO SAID JACKSONVILLE CTR'S 'SNITCH' HAD GONE OFF AND THAT SEPARATION BETWEEN THE TWO ACFT HAD DWINDLED TO 2.8 MI LATERAL AND 100' VERT. I HAVE NO COMPUTER TO TELL ME WHAT SEP I HAVE TO THE NEAREST TENTH OF A MI. I HAVE TO EYEBALL IT WHICH IS WHAT I DID. WHAT HAS HAPPENED BECAUSE OF THE 'SNITCH' IS THAT AIRSPACE EFFICIENCY HAD BEEN SIGNIFICANTLY REDUCED. CTLRS (ESPECIALLY IN THE CTRS) HAVE GREATLY INCREASED MINIMUM SEP STANDARDS SO AS TO PRECLUDE ANY CHANCE OF SETTING OFF THE SNITCH ALARMS. WHY DOESN'T THE SYS ALERT THE CTLR TO A POTENTIAL LOSS OF SEP INSTEAD OF TELLING HIM AFTER THE FACT THAT HE HAS HAD AN OPERATIONAL ERROR?

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.