Narrative:

I was working the final approach at the atlanta TRACON and observed an aircraft without a functioning transponder flying northbound through the finals approximately 12 mi west of atl. This aircraft was not observed by the final monitor position due to the prm (precision runway monitor) equipment's inability to track aircraft without a transponder. According to the procedures established at A80 (during ILS/prm approachs); the final monitor position is responsible for the safety of the aircraft and in fact is the only position at A80 that is in contact with the aircraft. The final monitor's prm equipment's inability to see non-transponder aircraft that are plainly visible on all the other radar displays is a serious safety violation and could lead to another cerritos; ca; type of disaster. The aircraft's TCAS equipment is also unable to see the target without a working transponder; therefore the pilot is completely unaware of the potentially dangerous situation. When the pilot is the lowest; busiest and most vulnerable to a collision; the air traffic controller responsible for his safety is working with a blindfold on. Also; without trying to be overly dramatic; if a terrorist wanted to deliberately fly into an aircraft; all he would have to do is turn his transponder to stand-by and he would become invisible to the pilot and the controllers using the FAA's newest (prm) equipment. Since the beginning of time; air traffic controllers have had the ability to observe a primary target on their radar display. With this new prm display; the FAA has taken a giant leap backwards.

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Original NASA ASRS Text

Title: AN ATL TRACON CTLR REPORTS POTENTIAL TFC CONFLICTS FOR ARRIVAL ACFT ON PRM APCHS BECAUSE NON TRANSPONDER ACFT ARE NOT SEEN BY PRM RADAR.

Narrative: I WAS WORKING THE FINAL APCH AT THE ATLANTA TRACON AND OBSERVED AN ACFT WITHOUT A FUNCTIONING XPONDER FLYING NBOUND THROUGH THE FINALS APPROX 12 MI W OF ATL. THIS ACFT WAS NOT OBSERVED BY THE FINAL MONITOR POS DUE TO THE PRM (PRECISION RWY MONITOR) EQUIP'S INABILITY TO TRACK ACFT WITHOUT A XPONDER. ACCORDING TO THE PROCS ESTABLISHED AT A80 (DURING ILS/PRM APCHS); THE FINAL MONITOR POS IS RESPONSIBLE FOR THE SAFETY OF THE ACFT AND IN FACT IS THE ONLY POS AT A80 THAT IS IN CONTACT WITH THE ACFT. THE FINAL MONITOR'S PRM EQUIP'S INABILITY TO SEE NON-XPONDER ACFT THAT ARE PLAINLY VISIBLE ON ALL THE OTHER RADAR DISPLAYS IS A SERIOUS SAFETY VIOLATION AND COULD LEAD TO ANOTHER CERRITOS; CA; TYPE OF DISASTER. THE ACFT'S TCAS EQUIP IS ALSO UNABLE TO SEE THE TARGET WITHOUT A WORKING XPONDER; THEREFORE THE PLT IS COMPLETELY UNAWARE OF THE POTENTIALLY DANGEROUS SITUATION. WHEN THE PLT IS THE LOWEST; BUSIEST AND MOST VULNERABLE TO A COLLISION; THE AIR TFC CTLR RESPONSIBLE FOR HIS SAFETY IS WORKING WITH A BLINDFOLD ON. ALSO; WITHOUT TRYING TO BE OVERLY DRAMATIC; IF A TERRORIST WANTED TO DELIBERATELY FLY INTO AN ACFT; ALL HE WOULD HAVE TO DO IS TURN HIS XPONDER TO STAND-BY AND HE WOULD BECOME INVISIBLE TO THE PLT AND THE CTLRS USING THE FAA'S NEWEST (PRM) EQUIP. SINCE THE BEGINNING OF TIME; AIR TFC CTLRS HAVE HAD THE ABILITY TO OBSERVE A PRIMARY TARGET ON THEIR RADAR DISPLAY. WITH THIS NEW PRM DISPLAY; THE FAA HAS TAKEN A GIANT LEAP BACKWARDS.

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.