Duplicate transponder code aircraft Y data tag swapped to aircraft X radar position.

Attributes
ACN	271431
Time
Date	199405
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : clt
State Reference	NC
Altitude	msl bound lower : 10000 msl bound upper : 10000
Environment
Flight Conditions	Mixed
Light	Night
Aircraft 1
Controlling Facilities	artcc : zjx
Operator	common carrier : air carrier
Make Model Name	Dash 8 Series Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	cruise other
Route In Use	enroute : direct enroute airway : clt
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Experience	controller military : 8 controller radar : 19 controller supervisory : 3
ASRS Report	271431
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	other anomaly other
Independent Detector	other controllera
Resolutory Action	other
Consequence	faa : investigated
Supplementary
Primary Problem	Navigational Facility
Air Traffic Incident	other

Narrative:

Aircraft X on chesterfield arrival over booze intersection. The handoff was accepted. After the handoff was accepted the track dropped off. Aircraft Y track started on. Aircraft X track in 'ambiguity' status. Aircraft Y was on the opposite side of the display 50 NM northwest of clt on the shine arrival. ARTS computer did not track the aircraft correctly. Both aircraft were assigned the same squawk by atl/ZJX computer systems. This caused great confusion during a complex arrival session with thunderstorms in the area. The arrival east controller discovered the problem and eventually straightened it out. Callback conversation with reporter revealed the following information: reporter stated he had been an automation specialist and recognized the problem immediately. 2 different ctrs had assigned the same transponder code to 2 different aircraft coming into clt airspace. The ARTS had made a correction and sent a new code to ZJX but the code did not get issued to aircraft Y. Aircraft X went into coast list and controller discovered the duplicate transponder code.

Original NASA ASRS Text

Title: DUPLICATE XPONDER CODE ACFT Y DATA TAG SWAPPED TO ACFT X RADAR POS.

Narrative: ACFT X ON CHESTERFIELD ARR OVER BOOZE INTXN. THE HANDOFF WAS ACCEPTED. AFTER THE HANDOFF WAS ACCEPTED THE TRACK DROPPED OFF. ACFT Y TRACK STARTED ON. ACFT X TRACK IN 'AMB' STATUS. ACFT Y WAS ON THE OPPOSITE SIDE OF THE DISPLAY 50 NM NW OF CLT ON THE SHINE ARR. ARTS COMPUTER DID NOT TRACK THE ACFT CORRECTLY. BOTH ACFT WERE ASSIGNED THE SAME SQUAWK BY ATL/ZJX COMPUTER SYSTEMS. THIS CAUSED GREAT CONFUSION DURING A COMPLEX ARR SESSION WITH TSTMS IN THE AREA. THE ARR E CTLR DISCOVERED THE PROB AND EVENTUALLY STRAIGHTENED IT OUT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED HE HAD BEEN AN AUTOMATION SPECIALIST AND RECOGNIZED THE PROB IMMEDIATELY. 2 DIFFERENT CTRS HAD ASSIGNED THE SAME XPONDER CODE TO 2 DIFFERENT ACFT COMING INTO CLT AIRSPACE. THE ARTS HAD MADE A CORRECTION AND SENT A NEW CODE TO ZJX BUT THE CODE DID NOT GET ISSUED TO ACFT Y. ACFT X WENT INTO COAST LIST AND CTLR DISCOVERED THE DUPLICATE XPONDER CODE.

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.