Cmh approach controller concerned with cenrap (combined center RAPCON) radar tracking as primary rad...

Attributes
ACN	539555
Time
Date	200203
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : cmh.airport
State Reference	OH
Altitude	msl bound lower : 1500 msl bound upper : 7000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : cmh.tracon
Make Model Name	Beech 1900
Flight Phase	climbout : intermediate altitude
Aircraft 2
Controlling Facilities	tracon : cmh.tracon
Make Model Name	Helicopter
Person 1
Affiliation	government : faa
Function	controller : departure
Qualification	controller : radar pilot : instrument
Experience	controller radar : 20 controller time certified in position1 : 8 flight time total : 1000
ASRS Report	539555
Person 2
Function	flight crew : captain oversight : pic
Events
Anomaly	other anomaly other
Independent Detector	atc equipment other atc equipment : radar other controllera
Resolutory Action	none taken : anomaly accepted
Supplementary
Problem Areas	Navigational Facility ATC Human Performance
Primary Problem	Navigational Facility
Situations
ATC Facility	computer equipment : cmh.tracon radar equipment : cmh.tracon

Narrative:

Due to primary radar failure (maintenance to fix problem), we were on cenrap. A B199 (beech 1900 turboprop) on departure from cmh, heading 180 degrees, the data block wouldn't stay. It kept dropping off until the aircraft reached 7000 ft MSL. It has been a while since I've operated on cenrap, but this is what I recall occurred on a regular basis when we did. Yet at the same time, the data block on a police helicopter at 1500 ft MSL was staying with that target just fine. The radar site is in london, oh. The helicopter was approximately 5 mi southwest of cmh. Traffic was light. The targets were approximately 5 mi apart (approximately 30 mi from the radar site). I don't see this as a radar problem as much as I see it as a radar data processing problem (ie, the X target was displayed the whole time -- the data block just would keep 'falling off'). We often call this 'cencrap.'

Original NASA ASRS Text

Title: CMH APCH CTLR CONCERNED WITH CENRAP (COMBINED CTR RAPCON) RADAR TRACKING AS PRIMARY RADAR FACILITY WAS OTS.

Narrative: DUE TO PRIMARY RADAR FAILURE (MAINT TO FIX PROB), WE WERE ON CENRAP. A B199 (BEECH 1900 TURBOPROP) ON DEP FROM CMH, HDG 180 DEGS, THE DATA BLOCK WOULDN'T STAY. IT KEPT DROPPING OFF UNTIL THE ACFT REACHED 7000 FT MSL. IT HAS BEEN A WHILE SINCE I'VE OPERATED ON CENRAP, BUT THIS IS WHAT I RECALL OCCURRED ON A REGULAR BASIS WHEN WE DID. YET AT THE SAME TIME, THE DATA BLOCK ON A POLICE HELI AT 1500 FT MSL WAS STAYING WITH THAT TARGET JUST FINE. THE RADAR SITE IS IN LONDON, OH. THE HELI WAS APPROX 5 MI SW OF CMH. TFC WAS LIGHT. THE TARGETS WERE APPROX 5 MI APART (APPROX 30 MI FROM THE RADAR SITE). I DON'T SEE THIS AS A RADAR PROB AS MUCH AS I SEE IT AS A RADAR DATA PROCESSING PROB (IE, THE X TARGET WAS DISPLAYED THE WHOLE TIME -- THE DATA BLOCK JUST WOULD KEEP 'FALLING OFF'). WE OFTEN CALL THIS 'CENCRAP.'

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.

Cmh approach controller concerned with cenrap (combined center RAPCON) radar tracking as primary radar facility was OTS.