Narrative:

I had aircraft X (C550) on a 040 degree vector at 4000 ft to dwh, approximately 25 mi wsw of iah VORTAC, when the ghost target of an actual working track (Y) appeared at the citation's 2 O'clock and about 10 mi position. This ghost track was at 4000 ft traveling at about 260 KTS. It appeared to be a very legitimate target. I initially thought it was an untagged, runaway aircraft from our control tower. It was not. Traffic was issued to aircraft X at about 6 mi, then again at about 4 mi. Simultaneous with the last traffic call, I instructed aircraft X to descend rapidly to 3000 ft and turn approximately 20 degrees left. The ghost target turned to a more westerly heading and descended to 3500 ft, again conflicting with the citation. I again issued traffic. The ghost target disappeared at about 1 mi behind aircraft X position, at the 5 O'clock position. After speaking with one of the TRACON's radar technicians, I was informed the increased activity of these targets has been caused by tree removal around our north ASR9 site, which has caused severe reflections. This is a very dangerous situation. If a pilot should lose control of his/her aircraft after being instructed to take evasive action around a non existing target, we all lose. The actual aircraft (ghost target) was 40 mi east of my traffic on a 15 mi ILS runway 27 approach to iah. Until I reported my occurrence to the duty supervisor, I did not know that we (the TRACON) had had previous reports about this very important matter. There has been, and is still (as of dec/xa/0) no action briefing item to clue us (line controllers) in to be alert for this possibility. This is totally unacceptable and extremely dangerous. I do not want to be involved in litigation over a crash because of an avoidable causal factor. Callback conversation with reporter revealed the following information: reporter advised maintenance was aware of this condition and that the condition will continue until the FAA technical center makes an automation fix for the problem. The condition is recent and frequent, expected to continue until the tree removal project is complete. The reporter advised the condition surfaced when tree cutting was initiated in the vicinity of the iah north radar site. Tree cutting is the preliminary action for the construction of a new parallel runway to runway 26. The ghost or false targets, are reported as caused from surface objects, reflecting radar returns. The reporter stated that maintenance provided him a radar printout of his situation. Maintenance stated that the false/ghost target was displayed as a 'strength 7,' and was tracked for 40 seconds. Apparently, the ghost target is never displayed on the radar scope of the controller actually controling the aircraft, but on all other radar indicators, 180 degrees from the actual target, always tracking the opposite direction of the reflected aircraft. This ghost target will display all tracked data information from the 'real' aircraft. The reporter advised that the greatest number of ghost targets are displayed within 10 mi of the north radar antenna, to as far as 30 mi, altitudes from 2000-6000 ft. The reporter has filed concerns with other FAA offices.

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Original NASA ASRS Text

Title: I90 CTLR INITIATES EVASIVE CTL INSTRUCTIONS TO C550 WHEN OBSERVING A GHOST E120 TRACK CONFLICTING WITH THE C550.

Narrative: I HAD ACFT X (C550) ON A 040 DEG VECTOR AT 4000 FT TO DWH, APPROX 25 MI WSW OF IAH VORTAC, WHEN THE GHOST TARGET OF AN ACTUAL WORKING TRACK (Y) APPEARED AT THE CITATION'S 2 O'CLOCK AND ABOUT 10 MI POS. THIS GHOST TRACK WAS AT 4000 FT TRAVELING AT ABOUT 260 KTS. IT APPEARED TO BE A VERY LEGITIMATE TARGET. I INITIALLY THOUGHT IT WAS AN UNTAGGED, RUNAWAY ACFT FROM OUR CTL TWR. IT WAS NOT. TFC WAS ISSUED TO ACFT X AT ABOUT 6 MI, THEN AGAIN AT ABOUT 4 MI. SIMULTANEOUS WITH THE LAST TFC CALL, I INSTRUCTED ACFT X TO DSND RAPIDLY TO 3000 FT AND TURN APPROX 20 DEGS L. THE GHOST TARGET TURNED TO A MORE WESTERLY HDG AND DSNDED TO 3500 FT, AGAIN CONFLICTING WITH THE CITATION. I AGAIN ISSUED TFC. THE GHOST TARGET DISAPPEARED AT ABOUT 1 MI BEHIND ACFT X POS, AT THE 5 O'CLOCK POS. AFTER SPEAKING WITH ONE OF THE TRACON'S RADAR TECHNICIANS, I WAS INFORMED THE INCREASED ACTIVITY OF THESE TARGETS HAS BEEN CAUSED BY TREE REMOVAL AROUND OUR N ASR9 SITE, WHICH HAS CAUSED SEVERE REFLECTIONS. THIS IS A VERY DANGEROUS SIT. IF A PLT SHOULD LOSE CTL OF HIS/HER ACFT AFTER BEING INSTRUCTED TO TAKE EVASIVE ACTION AROUND A NON EXISTING TARGET, WE ALL LOSE. THE ACTUAL ACFT (GHOST TARGET) WAS 40 MI E OF MY TFC ON A 15 MI ILS RWY 27 APCH TO IAH. UNTIL I RPTED MY OCCURRENCE TO THE DUTY SUPVR, I DID NOT KNOW THAT WE (THE TRACON) HAD HAD PREVIOUS RPTS ABOUT THIS VERY IMPORTANT MATTER. THERE HAS BEEN, AND IS STILL (AS OF DEC/XA/0) NO ACTION BRIEFING ITEM TO CLUE US (LINE CTLRS) IN TO BE ALERT FOR THIS POSSIBILITY. THIS IS TOTALLY UNACCEPTABLE AND EXTREMELY DANGEROUS. I DO NOT WANT TO BE INVOLVED IN LITIGATION OVER A CRASH BECAUSE OF AN AVOIDABLE CAUSAL FACTOR. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR ADVISED MAINT WAS AWARE OF THIS CONDITION AND THAT THE CONDITION WILL CONTINUE UNTIL THE FAA TECHNICAL CTR MAKES AN AUTOMATION FIX FOR THE PROB. THE CONDITION IS RECENT AND FREQUENT, EXPECTED TO CONTINUE UNTIL THE TREE REMOVAL PROJECT IS COMPLETE. THE RPTR ADVISED THE CONDITION SURFACED WHEN TREE CUTTING WAS INITIATED IN THE VICINITY OF THE IAH N RADAR SITE. TREE CUTTING IS THE PRELIMINARY ACTION FOR THE CONSTRUCTION OF A NEW PARALLEL RWY TO RWY 26. THE GHOST OR FALSE TARGETS, ARE RPTED AS CAUSED FROM SURFACE OBJECTS, REFLECTING RADAR RETURNS. THE RPTR STATED THAT MAINT PROVIDED HIM A RADAR PRINTOUT OF HIS SIT. MAINT STATED THAT THE FALSE/GHOST TARGET WAS DISPLAYED AS A 'STRENGTH 7,' AND WAS TRACKED FOR 40 SECONDS. APPARENTLY, THE GHOST TARGET IS NEVER DISPLAYED ON THE RADAR SCOPE OF THE CTLR ACTUALLY CTLING THE ACFT, BUT ON ALL OTHER RADAR INDICATORS, 180 DEGS FROM THE ACTUAL TARGET, ALWAYS TRACKING THE OPPOSITE DIRECTION OF THE REFLECTED ACFT. THIS GHOST TARGET WILL DISPLAY ALL TRACKED DATA INFO FROM THE 'REAL' ACFT. THE RPTR ADVISED THAT THE GREATEST NUMBER OF GHOST TARGETS ARE DISPLAYED WITHIN 10 MI OF THE N RADAR ANTENNA, TO AS FAR AS 30 MI, ALTS FROM 2000-6000 FT. THE RPTR HAS FILED CONCERNS WITH OTHER FAA OFFICES.

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.