Narrative:

This relates to the ability of a controller to 'see' the traffic after the changing of a digital acd scope. After sitting down to a control position I typed in my identify code in the acd, which brings up a menu of stored settings I made for each position. These settings control many different aspects of the scope (over 20 elements) that are usually done when the position is quiet (few aircraft). When I chose the south final button the settings went from the previous controller's settings to maximum intensity on all fields. At the time I was working 4 aircraft and about to take handoffs on 5 others. The shock from the flash of light took a few seconds to recover from, but I continued to work and reset the menu settings by typing into the keyboard the new intensity setting for each element. This led to me working away from the task at hand, the users, and keeping up with my planning. I could not slow down air carrier Y soon enough so his descent rate up more mileage putting him closer to the final on a right downwind and converging with air carrier Y. Air carrier Y had been turned to a right downwind (280 degrees) and descended to 2000 ft, but his speed was still 250 KTS with winds aloft pushing him towards the final. I am now working 8 planes with 4 flashing at me and an IFR C172 underneath (2000 ft) my downwind off fme to miss. Air carrier Y was on a vector of 130 degrees 17 mi west of the airport towards the FAF with air carrier X from the southeast turning west descending to 2000 ft after passing the cessna off fme and talking to 4 of the other aircraft in different phases of the approach. With half my settings close to normal, and very busy I saw air carrier X not making the descent fast enough, not slowing and too close to the final to make a turn for the approach. The only room to work with was further west 270 degrees and with a vector back to 120 degrees across the approach path and join from the left side of the ILS. Air carrier Y was still at 3000 ft aimed at a point 6 mi in front of air carrier X out of 2600 ft for 2000 ft on a heading of 270 degrees. My response was ask air carrier X to expedite to 2000 ft and traffic was exchanged between the two. Both aircraft passed 3 mi and 1000 ft apart, but too close for my experience. Air carrier X experienced an increase of 5 flight mi and some confusion for the vector across the final. Air carrier Y got to keep his speed up and made a fast final to the airport. We should be warned when equipment changes will affect our operating conditions so we can take preventative measures and avoid overloading controllers at peak traffic demands.

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Original NASA ASRS Text

Title: PCT CTLR DISTR BY ADJUSTING AUTOMATED RADAR SETTINGS EXPERIENCED MINIMUM RADAR SEPARATION.

Narrative: THIS RELATES TO THE ABILITY OF A CTLR TO 'SEE' THE TFC AFTER THE CHANGING OF A DIGITAL ACD SCOPE. AFTER SITTING DOWN TO A CTL POS I TYPED IN MY IDENT CODE IN THE ACD, WHICH BRINGS UP A MENU OF STORED SETTINGS I MADE FOR EACH POS. THESE SETTINGS CTL MANY DIFFERENT ASPECTS OF THE SCOPE (OVER 20 ELEMENTS) THAT ARE USUALLY DONE WHEN THE POS IS QUIET (FEW ACFT). WHEN I CHOSE THE SOUTH FINAL BUTTON THE SETTINGS WENT FROM THE PREVIOUS CTLR'S SETTINGS TO MAX INTENSITY ON ALL FIELDS. AT THE TIME I WAS WORKING 4 ACFT AND ABOUT TO TAKE HDOFS ON 5 OTHERS. THE SHOCK FROM THE FLASH OF LIGHT TOOK A FEW SECONDS TO RECOVER FROM, BUT I CONTINUED TO WORK AND RESET THE MENU SETTINGS BY TYPING INTO THE KEYBOARD THE NEW INTENSITY SETTING FOR EACH ELEMENT. THIS LED TO ME WORKING AWAY FROM THE TASK AT HAND, THE USERS, AND KEEPING UP WITH MY PLANNING. I COULD NOT SLOW DOWN ACR Y SOON ENOUGH SO HIS DSCNT RATE UP MORE MILEAGE PUTTING HIM CLOSER TO THE FINAL ON A R DOWNWIND AND CONVERGING WITH ACR Y. ACR Y HAD BEEN TURNED TO A R DOWNWIND (280 DEGS) AND DSNDED TO 2000 FT, BUT HIS SPD WAS STILL 250 KTS WITH WINDS ALOFT PUSHING HIM TOWARDS THE FINAL. I AM NOW WORKING 8 PLANES WITH 4 FLASHING AT ME AND AN IFR C172 UNDERNEATH (2000 FT) MY DOWNWIND OFF FME TO MISS. ACR Y WAS ON A VECTOR OF 130 DEGS 17 MI W OF THE ARPT TOWARDS THE FAF WITH ACR X FROM THE SE TURNING W DSNDING TO 2000 FT AFTER PASSING THE CESSNA OFF FME AND TALKING TO 4 OF THE OTHER ACFT IN DIFFERENT PHASES OF THE APCH. WITH HALF MY SETTINGS CLOSE TO NORMAL, AND VERY BUSY I SAW ACR X NOT MAKING THE DSCNT FAST ENOUGH, NOT SLOWING AND TOO CLOSE TO THE FINAL TO MAKE A TURN FOR THE APCH. THE ONLY ROOM TO WORK WITH WAS FURTHER W 270 DEGS AND WITH A VECTOR BACK TO 120 DEGS ACROSS THE APCH PATH AND JOIN FROM THE L SIDE OF THE ILS. ACR Y WAS STILL AT 3000 FT AIMED AT A POINT 6 MI IN FRONT OF ACR X OUT OF 2600 FT FOR 2000 FT ON A HDG OF 270 DEGS. MY RESPONSE WAS ASK ACR X TO EXPEDITE TO 2000 FT AND TFC WAS EXCHANGED BTWN THE TWO. BOTH ACFT PASSED 3 MI AND 1000 FT APART, BUT TOO CLOSE FOR MY EXPERIENCE. ACR X EXPERIENCED AN INCREASE OF 5 FLT MI AND SOME CONFUSION FOR THE VECTOR ACROSS THE FINAL. ACR Y GOT TO KEEP HIS SPD UP AND MADE A FAST FINAL TO THE ARPT. WE SHOULD BE WARNED WHEN EQUIP CHANGES WILL AFFECT OUR OPERATING CONDITIONS SO WE CAN TAKE PREVENTATIVE MEASURES AND AVOID OVERLOADING CTLRS AT PEAK TFC DEMANDS.

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.