Narrative:

There is a long-standing long-term safety issue associated with the ASR-11. We work with two ASR-11 systems; one at sgf and one at mzu. Since the commissioning; we have had issues with numerous (in the hundreds at times) extraneous primary targets appearing on the radar scope. These primary targets are generally stationary and last for anywhere from several sweeps to several hours. As we are required to issue traffic on all visible primary targets; this can create an unrealistic workload on air traffic. The distraction of so many primary traffic calls could create a degradation of safety. This issue was reported as a serious problem during the ASR-11's iot&east process (independent operational testing and evaluation); yet the system was certified and commissioned in spite of that fact. We have continuously reported the issue to the FAA and it has been consistently been swept under the rug. The official response has been that this is caused by migratory birds; temperature inversion or ap. The conjecture that this could be caused by birds is ludicrous. Supposedly the radar only tracks primary targets with sustained speeds of 60 knots or more. While some birds may be able to sustain those speeds in short bursts; I'm fairly sure that hundreds of racing birds at a time would be noticeable from the ground. Additionally; these targets are more often than not stationary; thus negating this argument. Regardless of the cause of this issue; it is a safety problem and needs to be addressed and mitigated.

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Original NASA ASRS Text

Title: SGF CTLR DESCRIBED AN ONGOING ASR-11 SAFETY ISSUE; IE; EXTRANEOUS TARGETS; THAT APPEAR ON THE DISPLAYS.

Narrative: THERE IS A LONG-STANDING LONG-TERM SAFETY ISSUE ASSOCIATED WITH THE ASR-11. WE WORK WITH TWO ASR-11 SYSTEMS; ONE AT SGF AND ONE AT MZU. SINCE THE COMMISSIONING; WE HAVE HAD ISSUES WITH NUMEROUS (IN THE HUNDREDS AT TIMES) EXTRANEOUS PRIMARY TARGETS APPEARING ON THE RADAR SCOPE. THESE PRIMARY TARGETS ARE GENERALLY STATIONARY AND LAST FOR ANYWHERE FROM SEVERAL SWEEPS TO SEVERAL HOURS. AS WE ARE REQUIRED TO ISSUE TRAFFIC ON ALL VISIBLE PRIMARY TARGETS; THIS CAN CREATE AN UNREALISTIC WORKLOAD ON AIR TRAFFIC. THE DISTRACTION OF SO MANY PRIMARY TRAFFIC CALLS COULD CREATE A DEGRADATION OF SAFETY. THIS ISSUE WAS REPORTED AS A SERIOUS PROBLEM DURING THE ASR-11'S IOT&E PROCESS (INDEPENDENT OPERATIONAL TESTING AND EVALUATION); YET THE SYSTEM WAS CERTIFIED AND COMMISSIONED IN SPITE OF THAT FACT. WE HAVE CONTINUOUSLY REPORTED THE ISSUE TO THE FAA AND IT HAS BEEN CONSISTENTLY BEEN SWEPT UNDER THE RUG. THE OFFICIAL RESPONSE HAS BEEN THAT THIS IS CAUSED BY MIGRATORY BIRDS; TEMPERATURE INVERSION OR AP. THE CONJECTURE THAT THIS COULD BE CAUSED BY BIRDS IS LUDICROUS. SUPPOSEDLY THE RADAR ONLY TRACKS PRIMARY TARGETS WITH SUSTAINED SPEEDS OF 60 KNOTS OR MORE. WHILE SOME BIRDS MAY BE ABLE TO SUSTAIN THOSE SPEEDS IN SHORT BURSTS; I'M FAIRLY SURE THAT HUNDREDS OF RACING BIRDS AT A TIME WOULD BE NOTICEABLE FROM THE GROUND. ADDITIONALLY; THESE TARGETS ARE MORE OFTEN THAN NOT STATIONARY; THUS NEGATING THIS ARGUMENT. REGARDLESS OF THE CAUSE OF THIS ISSUE; IT IS A SAFETY PROBLEM AND NEEDS TO BE ADDRESSED AND MITIGATED.

Data retrieved from NASA's ASRS site as of January 2009 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.