RPTR CLAIMS THAT AN ACFT FACTORY ON SAV ARPT CONDUCTS RAMP XPONDER TESTS THAT ARE DISRUPTIVE TO THE FACILITIES RADAR SYS. THE RPTR STATES THAT THE TESTING CAUSES RING AROUND; CLUTTER; TAG SWAPPING; AND APPARENTLY GIVES ARRS AND DEPS FALSE TCASII WARNINGS.

Narrative

FAA ATC MGMNT AT SAVANNAH ATCT HAS LONG BEEN AWARE OF THE FACT THAT ACFT FACTORY HAS BEEN DOING DISRUPTIVE XPONDER CHKS ON SAV ARPT. THESE DISRUPTIVE XPONDER(S) CHKS ON THE ACFT RAMP/FACTORY CAUSE: 1) TCASII INCIDENTS FOR ARR/DEP SAV ARPT. ENRTE TCASII INCIDENTS -- GND MODE C IS RUN UP FROM 100 FT UP AS HIGH AS FL430. 2) GND BASED XPONDERS CAUSE RADAR BEACON 'RING AROUND' AND DISRUPTIVE RADAR CLUTTER. 3) BEACON CODES USED BY ACFT MAINT ARE USUALLY IFR CODES; USED BY REAL ACTIVE ACFT; CAUSING NON-ARTS DEPS AND/OR TAG SWAPPING. 4) SOMETIMES THE BEACON CODE IS XXXX; WHICH IS THE 'SUSPECT' DRUG ACFT CODE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR CLAIMS THE PROB HAS EXISTED AT LEAST SINCE 1995 WHEN HE STARTED WORKING AT SAV. RPTR STATED THE INTERFERENCE OCCURS SEVERAL TIMES A WK; USUALLY ON WKDAYS WHEN THE ACFT FACILITY IS WORKING. WHEN AN INTERFERENCE PROB OCCURS; HE SAYS THE SUPVRS WILL CALL THE ACFT OFFICE AND MOST OF THE TIME ARE TOLD THAT THEY ARE NOT WORKING. THE RPTR SAID WHEN THE FACTORY IS TESTING XPONDERS; THEY WILL USE CODES 1200; 1234; OR 1236. THEY WILL ALSO OCCASIONALLY USE IFR CODES. THE RPTR SAID AN INCIDENT HAPPENED ABOUT A YR AGO AT SAV WHERE A FLC ON SHORT FINAL RECEIVED A TCASII ALARM AND ABORTED THEIR LNDG. NO OTHER TFC WAS IN THE AREA AT THE TIME. THE RPTR FEELS MGMNT DOESN'T CONSIDER THE OCCASIONAL INTERFERENCE A PROB.