Narrative:

A crj was on the atl ILS-prm runway 28 approach. When the aircraft checked on tower frequency the prm monitor controller could not find the data block; or any type of target indicator; on his prm display. He looked at the racd overhead and observed the target established on the final. On an 8 1/2 mi final the aircraft appeared on the prm display and tagged up. This aircraft was on final approach during triple ILS approachs with aircraft on final for runways 27L and 26R. For 10 mi this aircraft was on final approach and not displayed on the prm displays. This equipment is unreliable and should not be used for ATC until this situation can be prevented.

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Original NASA ASRS Text

Title: A80 CTLR DESCRIBED PRM DISPLAY PROBLEM; TFC WAS NOT VISIBLE ON THE PRM MONITOR UNTIL REACHING 8 1/2 MILE FINAL.

Narrative: A CRJ WAS ON THE ATL ILS-PRM RWY 28 APCH. WHEN THE ACFT CHKED ON TWR FREQ THE PRM MONITOR CTLR COULD NOT FIND THE DATA BLOCK; OR ANY TYPE OF TARGET INDICATOR; ON HIS PRM DISPLAY. HE LOOKED AT THE RACD OVERHEAD AND OBSERVED THE TARGET ESTABLISHED ON THE FINAL. ON AN 8 1/2 MI FINAL THE ACFT APPEARED ON THE PRM DISPLAY AND TAGGED UP. THIS ACFT WAS ON FINAL APCH DURING TRIPLE ILS APCHS WITH ACFT ON FINAL FOR RWYS 27L AND 26R. FOR 10 MI THIS ACFT WAS ON FINAL APCH AND NOT DISPLAYED ON THE PRM DISPLAYS. THIS EQUIP IS UNRELIABLE AND SHOULD NOT BE USED FOR ATC UNTIL THIS SITUATION CAN BE PREVENTED.

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.