Narrative:

There is concern about the unreliable performance of the ASR-8 radar at tower/TRACON. In the 72 hours prior to jul/sun, there were a number of sector pulse faults. In layman terms, this means that the automated radar terminal system (ARTS) appears to shut off then come back on with data blocks and targets up to 180 degrees out of phase. It will then shut down again and the data blocks will reappear in their original position. There was no attempt by management to take the radar OTS until jul/sun, when the union intervened. The same type of event occurred 2 weeks prior to the sunday, and again there was no attempt to take the radar OTS until the union representative intervened. He had been on vacation for 10 days and the faculty had been having radar problems for 7 days. A ucr has been filed because of this recurring problem. On jul/sun/96 the tower was without radar for nearly 6 hours. During the incident 2 weeks prior, the facility was without radar for 2 days. As of this writing, airways faculties has temporarily fixed the problem by limiting how the radar information is sent to the tower. We only use 1 path from the radar site to the tower. We have 2, a primary and a backup. The radar is locked to one azimuth pulse generator. We have 2, a primary and a backup. Airways faculties shut down the equipment that automatically switches the azimuth pulse generator from the primary to the backup when a problem occurs. They feel the problem is the switching equipment called dantell. Since this was done we have not had a sector pulse fault, which is good. However, what I see as the problem now is that we don't have a readily available backup system if the azimuth pulse generator or the path fails. There is a history of apg and path problems here. I do not believe airways faculties knows what is wrong with the radar. When it happened the first time, we were told that the problem was in the microwave link from the radar site to the tower. Now it's this dantell thing. Also keep in mind that this equipment is probably 20-30 yrs old. Callback conversation with reporter revealed the following information: reporter stated the problem was fixed by removing radar equipment surge protectors.

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Original NASA ASRS Text

Title: PROB WITH THE FACILITY RADAR AFFECTING ARTS DATA BLOCKS AND TARGET CORRELATION RELATIVE TO SECTOR PULSE FAULTS. THE RADAR WAS OTS FOR OVER 2 DAYS.

Narrative: THERE IS CONCERN ABOUT THE UNRELIABLE PERFORMANCE OF THE ASR-8 RADAR AT TWR/TRACON. IN THE 72 HRS PRIOR TO JUL/SUN, THERE WERE A NUMBER OF SECTOR PULSE FAULTS. IN LAYMAN TERMS, THIS MEANS THAT THE AUTOMATED RADAR TERMINAL SYS (ARTS) APPEARS TO SHUT OFF THEN COME BACK ON WITH DATA BLOCKS AND TARGETS UP TO 180 DEGS OUT OF PHASE. IT WILL THEN SHUT DOWN AGAIN AND THE DATA BLOCKS WILL REAPPEAR IN THEIR ORIGINAL POS. THERE WAS NO ATTEMPT BY MGMNT TO TAKE THE RADAR OTS UNTIL JUL/SUN, WHEN THE UNION INTERVENED. THE SAME TYPE OF EVENT OCCURRED 2 WKS PRIOR TO THE SUNDAY, AND AGAIN THERE WAS NO ATTEMPT TO TAKE THE RADAR OTS UNTIL THE UNION REPRESENTATIVE INTERVENED. HE HAD BEEN ON VACATION FOR 10 DAYS AND THE FACULTY HAD BEEN HAVING RADAR PROBS FOR 7 DAYS. A UCR HAS BEEN FILED BECAUSE OF THIS RECURRING PROB. ON JUL/SUN/96 THE TWR WAS WITHOUT RADAR FOR NEARLY 6 HRS. DURING THE INCIDENT 2 WKS PRIOR, THE FACILITY WAS WITHOUT RADAR FOR 2 DAYS. AS OF THIS WRITING, AIRWAYS FACULTIES HAS TEMPORARILY FIXED THE PROB BY LIMITING HOW THE RADAR INFO IS SENT TO THE TWR. WE ONLY USE 1 PATH FROM THE RADAR SITE TO THE TWR. WE HAVE 2, A PRIMARY AND A BACKUP. THE RADAR IS LOCKED TO ONE AZIMUTH PULSE GENERATOR. WE HAVE 2, A PRIMARY AND A BACKUP. AIRWAYS FACULTIES SHUT DOWN THE EQUIP THAT AUTOMATICALLY SWITCHES THE AZIMUTH PULSE GENERATOR FROM THE PRIMARY TO THE BACKUP WHEN A PROB OCCURS. THEY FEEL THE PROB IS THE SWITCHING EQUIP CALLED DANTELL. SINCE THIS WAS DONE WE HAVE NOT HAD A SECTOR PULSE FAULT, WHICH IS GOOD. HOWEVER, WHAT I SEE AS THE PROB NOW IS THAT WE DON'T HAVE A READILY AVAILABLE BACKUP SYS IF THE AZIMUTH PULSE GENERATOR OR THE PATH FAILS. THERE IS A HISTORY OF APG AND PATH PROBS HERE. I DO NOT BELIEVE AIRWAYS FACULTIES KNOWS WHAT IS WRONG WITH THE RADAR. WHEN IT HAPPENED THE FIRST TIME, WE WERE TOLD THAT THE PROB WAS IN THE MICROWAVE LINK FROM THE RADAR SITE TO THE TWR. NOW IT'S THIS DANTELL THING. ALSO KEEP IN MIND THAT THIS EQUIP IS PROBABLY 20-30 YRS OLD. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THE PROB WAS FIXED BY REMOVING RADAR EQUIP SURGE PROTECTORS.

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.