ARTS III failures at mem may have caused a loss of separation between 2 SF34 aircraft.

Attributes
ACN	557099
Time
Date	200208
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : mem.airport
State Reference	TN
Altitude	msl single value : 4800
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : mem.tracon tower : lfpg.tower
Operator	common carrier : air carrier
Make Model Name	SF 340A
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : mem.tracon
Operator	common carrier : air carrier
Make Model Name	SF 340A
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Experience	controller radar : 20 controller time certified in position1 : 3 flight time total : 160
ASRS Report	557099
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation other anomaly other
Independent Detector	other controllera other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance
Consequence	faa : investigated
Miss Distance	horizontal : 6000 vertical : 0
Supplementary
Problem Areas	ATC Facility ATC Human Performance Flight Crew Human Performance
Primary Problem	Ambiguous

Narrative:

ARTS III failed (twice). Aircraft #1 was on 090 degree vector talking to me (runway 27 final controller). Aircraft #2 was on a 360 degree vector (talking to east arrival). During this confusion of the outage, east arrival failed to switch the northbound (aircraft #2) to my frequency. Aircraft #2 received an RA. I issued aircraft #1 an immediate left to 330 degrees and descend to 3000 ft. Aircraft #1 said they had aircraft #2 in sight and were instructed to maintain visual. Callback conversation with reporter revealed the following information: reporter stated that the ARTS III equipment failed during a moderate to heavy traffic session. He said the failure lasted about 2 1/2 mins and a couple of mins later a second failure occurred for about 2-3 mins. He said during the outages, all data blocks diminished and displayed only the aircraft altitude. No cause was given for the failure. Asked if any loss of separation had occurred because of the outage, the reporter said he didn't think so, that the WX was excellent and visual separation was used by the controllers. The reporter also stated that ARTS III outages at mem are rare.

Original NASA ASRS Text

Title: ARTS III FAILURES AT MEM MAY HAVE CAUSED A LOSS OF SEPARATION BTWN 2 SF34 ACFT.

Narrative: ARTS III FAILED (TWICE). ACFT #1 WAS ON 090 DEG VECTOR TALKING TO ME (RWY 27 FINAL CTLR). ACFT #2 WAS ON A 360 DEG VECTOR (TALKING TO E ARR). DURING THIS CONFUSION OF THE OUTAGE, E ARR FAILED TO SWITCH THE NBOUND (ACFT #2) TO MY FREQ. ACFT #2 RECEIVED AN RA. I ISSUED ACFT #1 AN IMMEDIATE L TO 330 DEGS AND DSND TO 3000 FT. ACFT #1 SAID THEY HAD ACFT #2 IN SIGHT AND WERE INSTRUCTED TO MAINTAIN VISUAL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT THE ARTS III EQUIP FAILED DURING A MODERATE TO HVY TFC SESSION. HE SAID THE FAILURE LASTED ABOUT 2 1/2 MINS AND A COUPLE OF MINS LATER A SECOND FAILURE OCCURRED FOR ABOUT 2-3 MINS. HE SAID DURING THE OUTAGES, ALL DATA BLOCKS DIMINISHED AND DISPLAYED ONLY THE ACFT ALT. NO CAUSE WAS GIVEN FOR THE FAILURE. ASKED IF ANY LOSS OF SEPARATION HAD OCCURRED BECAUSE OF THE OUTAGE, THE RPTR SAID HE DIDN'T THINK SO, THAT THE WX WAS EXCELLENT AND VISUAL SEPARATION WAS USED BY THE CTLRS. THE RPTR ALSO STATED THAT ARTS III OUTAGES AT MEM ARE RARE.

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.