Radar loss and intermittent targets occur since ASR-9 was installed.

Attributes
ACN	257959
Time
Date	199311
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : tpa
State Reference	FL
Altitude	msl bound lower : 4000 msl bound upper : 4000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : tpa
Operator	general aviation : personal
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
ASRS Report	257959
Person 2
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument
Events
Anomaly	other anomaly other
Independent Detector	other controllera
Resolutory Action	none taken : unable
Consequence	Other
Supplementary
Primary Problem	Navigational Facility
Air Traffic Incident	other

Narrative:

Tpa radar system operating on beacon only during ASR 9 installation. Aircraft has good beacon target with ZMA. Aircraft enters tpa airspace and begins to show a weak beacon target. Radar contact is lost at 4000 ft 20 southeast of tpa, and does not return to a good beacon target until 10 southeast of tpa. Pilot reported no other problems with transponder. I solicited the pilot to cancel IFR, and he concurred. Tpa beacon system has been unreliable on a continuing basis for the yr I have bee at tpa. The radar system is substandard to the other system I have worked, which include stl, sdf, and iad. Aircraft often coast and are told their xponders are inoperative when they have not had other problems on their entire route of flight. On nov/xx/93, I worked an small transport X at 7000 ft MSL on V-157 sbound to lal then direct srq. His mode C became inoperative 25 NM north of lal and did not show mode C again until 15-20 NM wsw of lal. I called ZJX to verify that they were showing a strong beacon and mode C on the aircraft. They showed the aircraft at 7000 while I had no mode C at all. Airways facilities was advised at tpa, however, I believe no action was taken. This continuing problem of unreliable or no mode C or erroneous mode C is a hazard to safety at tpa.

Original NASA ASRS Text

Title: RADAR LOSS AND INTERMITTENT TARGETS OCCUR SINCE ASR-9 WAS INSTALLED.

Narrative: TPA RADAR SYS OPERATING ON BEACON ONLY DURING ASR 9 INSTALLATION. ACFT HAS GOOD BEACON TARGET WITH ZMA. ACFT ENTERS TPA AIRSPACE AND BEGINS TO SHOW A WEAK BEACON TARGET. RADAR CONTACT IS LOST AT 4000 FT 20 SE OF TPA, AND DOES NOT RETURN TO A GOOD BEACON TARGET UNTIL 10 SE OF TPA. PLT RPTED NO OTHER PROBS WITH XPONDER. I SOLICITED THE PLT TO CANCEL IFR, AND HE CONCURRED. TPA BEACON SYS HAS BEEN UNRELIABLE ON A CONTINUING BASIS FOR THE YR I HAVE BEE AT TPA. THE RADAR SYS IS SUBSTANDARD TO THE OTHER SYS I HAVE WORKED, WHICH INCLUDE STL, SDF, AND IAD. ACFT OFTEN COAST AND ARE TOLD THEIR XPONDERS ARE INOP WHEN THEY HAVE NOT HAD OTHER PROBS ON THEIR ENTIRE RTE OF FLT. ON NOV/XX/93, I WORKED AN SMT X AT 7000 FT MSL ON V-157 SBOUND TO LAL THEN DIRECT SRQ. HIS MODE C BECAME INOP 25 NM N OF LAL AND DID NOT SHOW MODE C AGAIN UNTIL 15-20 NM WSW OF LAL. I CALLED ZJX TO VERIFY THAT THEY WERE SHOWING A STRONG BEACON AND MODE C ON THE ACFT. THEY SHOWED THE ACFT AT 7000 WHILE I HAD NO MODE C AT ALL. AIRWAYS FACILITIES WAS ADVISED AT TPA, HOWEVER, I BELIEVE NO ACTION WAS TAKEN. THIS CONTINUING PROB OF UNRELIABLE OR NO MODE C OR ERRONEOUS MODE C IS A HAZARD TO SAFETY AT TPA.

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.