Controller misident radar displayed altitude data for climbing B738 resulting in loss of separation.

Attributes
ACN	568867
Time
Date	200212
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	navaid : fwa.vortac
State Reference	IN
Environment
Weather Elements	Turbulence Thunderstorm
Light	Night
Aircraft 1
Controlling Facilities	artcc : zid.artcc
Operator	common carrier : air carrier
Make Model Name	Regional Jet 200 ER&LR
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zid.artcc
Operator	common carrier : air carrier
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 32 controller time certified in position1 : 28
ASRS Report	568867
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	conflict : airborne critical non adherence : required legal separation non adherence : published procedure
Independent Detector	atc equipment : conflict alert aircraft equipment : tcas other controllera
Resolutory Action	flight crew : took evasive action flight crew : returned to assigned altitude
Consequence	faa : investigated
Miss Distance	horizontal : 21000 vertical : 200
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Air carrier X was at FL290 msp-fwa-ric. Air carrier Y was a departure off cmh going to fwa-mdw. Air carrier Y called on, climbing to FL230, later was cleared to FL260 for traffic at FL270. Air carrier Y was clear of traffic and cleared to FL290. The data, when updated, showed FL280 in data block. I thought I had cleared air carrier Y to FL280. When air carrier Y was at FL280 in data block, traffic was called, traffic 12 O'clock regional jet 1000 ft above, when I saw air carrier Y at FL284. I tried to call air carrier Y to verify his altitude. No quick response, so I tried to climb and turn other air carrier X, which was blocked by unknown call. Then air carrier Y called turning 50 degrees left and then air carrier X said he was at FL295. Air carrier Y said clear of traffic descending to FL280 and was told to maintain FL280. Air carrier X did have a TCASII alert -- that is why he climbed to FL295.

Original NASA ASRS Text

Title: CTLR MISIDENT RADAR DISPLAYED ALT DATA FOR CLBING B738 RESULTING IN LOSS OF SEPARATION.

Narrative: ACR X WAS AT FL290 MSP-FWA-RIC. ACR Y WAS A DEP OFF CMH GOING TO FWA-MDW. ACR Y CALLED ON, CLBING TO FL230, LATER WAS CLRED TO FL260 FOR TFC AT FL270. ACR Y WAS CLR OF TFC AND CLRED TO FL290. THE DATA, WHEN UPDATED, SHOWED FL280 IN DATA BLOCK. I THOUGHT I HAD CLRED ACR Y TO FL280. WHEN ACR Y WAS AT FL280 IN DATA BLOCK, TFC WAS CALLED, TFC 12 O'CLOCK REGIONAL JET 1000 FT ABOVE, WHEN I SAW ACR Y AT FL284. I TRIED TO CALL ACR Y TO VERIFY HIS ALT. NO QUICK RESPONSE, SO I TRIED TO CLB AND TURN OTHER ACR X, WHICH WAS BLOCKED BY UNKNOWN CALL. THEN ACR Y CALLED TURNING 50 DEGS L AND THEN ACR X SAID HE WAS AT FL295. ACR Y SAID CLR OF TFC DSNDING TO FL280 AND WAS TOLD TO MAINTAIN FL280. ACR X DID HAVE A TCASII ALERT -- THAT IS WHY HE CLBED TO FL295.

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.