Narrative:

Radar technician was 'changing a card' for our radar. He forgot to FLIP a switch which resulted in a 4 min radar outage. Prior experience caused air traffic to ensure that this maintenance was to be done during a slow traffic period, ie, saturday morning. We had 4 aircraft in our airspace at the time of the incident. All were transitioned to non radar without losing separation. Human errors occur but seem to plague my facility more than most. As always, had we been busier when this occurred, safety would have been less than what is necessary. About 1 hour later, when the radar technician tried to return mode-south, the radar failed again and we had to return to our backup system.

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Original NASA ASRS Text

Title: ATCT LCL CTLR EXPERIENCES RADAR FAILURE DURING INTRAFAC COORD RADAR MAINT PROC. CTLR BELIEVES HIS FACILITY HAS MORE THAN THEIR SHARE OF EQUIP OUTAGES.

Narrative: RADAR TECHNICIAN WAS 'CHANGING A CARD' FOR OUR RADAR. HE FORGOT TO FLIP A SWITCH WHICH RESULTED IN A 4 MIN RADAR OUTAGE. PRIOR EXPERIENCE CAUSED AIR TFC TO ENSURE THAT THIS MAINT WAS TO BE DONE DURING A SLOW TFC PERIOD, IE, SATURDAY MORNING. WE HAD 4 ACFT IN OUR AIRSPACE AT THE TIME OF THE INCIDENT. ALL WERE TRANSITIONED TO NON RADAR WITHOUT LOSING SEPARATION. HUMAN ERRORS OCCUR BUT SEEM TO PLAGUE MY FACILITY MORE THAN MOST. AS ALWAYS, HAD WE BEEN BUSIER WHEN THIS OCCURRED, SAFETY WOULD HAVE BEEN LESS THAN WHAT IS NECESSARY. ABOUT 1 HR LATER, WHEN THE RADAR TECHNICIAN TRIED TO RETURN MODE-S, THE RADAR FAILED AGAIN AND WE HAD TO RETURN TO OUR BACKUP SYS.

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.