Small aircraft X had less than standard separation from air carrier Y. System error.

Attributes
ACN	174536
Time
Date	199104
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : jax
State Reference	FL
Altitude	msl bound lower : 7000 msl bound upper : 8000
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Controlling Facilities	tracon : jax
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Fixed Gear
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
ASRS Report	174536
Person 2
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation non adherence : published procedure
Independent Detector	other controllera
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Miss Distance	horizontal : 12000 vertical : 0
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

As for other equipment, the aural or visibility C/a did not sound. Small aircraft X was established at 7000' MSL on an arwy that crosses a descent corridor for jax. Air carrier Y was issued a heading and descent through the altitude of small aircraft X, which should have provided adequate vertical and horizontal sep. The controller recognized the decrease in sep to less than 1000' and 3 mi at the time a frequency change was to be made to air carrier Y. Factors: workload, 9-12 aircraft; arwys crossing descent corridor; multiple cloud layers and rain showers; LOA's requiring aircraft to be at wrong altitude for direction of flight; C/a feature of the ARTS IIIA radar did not function; and coordinator position manned, but controller was busy performing other coordination.

Original NASA ASRS Text

Title: SMA X HAD LESS THAN STANDARD SEPARATION FROM ACR Y. SYSTEM ERROR.

Narrative: AS FOR OTHER EQUIP, THE AURAL OR VIS C/A DID NOT SOUND. SMA X WAS ESTABLISHED AT 7000' MSL ON AN ARWY THAT CROSSES A DSNT CORRIDOR FOR JAX. ACR Y WAS ISSUED A HDG AND DSNT THROUGH THE ALT OF SMA X, WHICH SHOULD HAVE PROVIDED ADEQUATE VERT AND HORIZ SEP. THE CTLR RECOGNIZED THE DECREASE IN SEP TO LESS THAN 1000' AND 3 MI AT THE TIME A FREQ CHANGE WAS TO BE MADE TO ACR Y. FACTORS: WORKLOAD, 9-12 ACFT; ARWYS XING DSNT CORRIDOR; MULTIPLE CLOUD LAYERS AND RAIN SHOWERS; LOA'S REQUIRING ACFT TO BE AT WRONG ALT FOR DIRECTION OF FLT; C/A FEATURE OF THE ARTS IIIA RADAR DID NOT FUNCTION; AND COORDINATOR POS MANNED, BUT CTLR WAS BUSY PERFORMING OTHER COORD.

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.