Narrative:

FL240 just east of civet, I was getting ready to enter landing flight data when the mcdu displayed 'enter field data' then 'speed error' at civet. I attempted to clear and the first officer's and captain's mcdu's froze. We checked the flight manual and ACARS maintenance. Only input was to pull and reset the circuit breakers. This was accomplished with no change. The captain continued to fly the civet 4 arrival as I troubleshot and worked the radio, and set altimeter. It was decided to load the ILS runway 25L at lax manually via the rmp. This was accomplished and the captain flew the approach. We entered WX approximately 4000 ft and broke out at 2000 ft. We could not arm the approach and the localizer failed to arm 2 times. We could not enter field data, approach, or activate and confirm the navigation display showed us slightly right of course and the captain began to correct, then we broke out. This was when tower asked if we had the per course and were flying it. I replied correcting, and then tower directed a go around, heading 180 degrees, altitude 2000 ft, contact approach. We applied missed approach procedure and were vectored around for another uneventful approach and landing. Lessons learned, xchks are different due to manually entering data and computers locked up. Lack of familiarity with manual entery and flying ILS procedures. We should have informed ATC of our equipment degrade so closer monitoring could have been accomplished. Supplemental information from acn 543856: some minor confusion making sure radios were correctly setup. Drifted north of course. Tower initiated go around. Normal approach and landing followed. Mostly visual.

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Original NASA ASRS Text

Title: AN A320 CREW, ON APCH TO LAX, EXPERIENCED AN FCU PROB, REQUIRING THE ILS TO BE FLOWN MANUALLY. A R DEV OF COURSE RESULTED IN A TWR INITIATED GAR.

Narrative: FL240 JUST E OF CIVET, I WAS GETTING READY TO ENTER LNDG FLT DATA WHEN THE MCDU DISPLAYED 'ENTER FIELD DATA' THEN 'SPD ERROR' AT CIVET. I ATTEMPTED TO CLR AND THE FO'S AND CAPT'S MCDU'S FROZE. WE CHKED THE FLT MANUAL AND ACARS MAINT. ONLY INPUT WAS TO PULL AND RESET THE CIRCUIT BREAKERS. THIS WAS ACCOMPLISHED WITH NO CHANGE. THE CAPT CONTINUED TO FLY THE CIVET 4 ARR AS I TROUBLESHOT AND WORKED THE RADIO, AND SET ALTIMETER. IT WAS DECIDED TO LOAD THE ILS RWY 25L AT LAX MANUALLY VIA THE RMP. THIS WAS ACCOMPLISHED AND THE CAPT FLEW THE APCH. WE ENTERED WX APPROX 4000 FT AND BROKE OUT AT 2000 FT. WE COULD NOT ARM THE APCH AND THE LOC FAILED TO ARM 2 TIMES. WE COULD NOT ENTER FIELD DATA, APCH, OR ACTIVATE AND CONFIRM THE NAV DISPLAY SHOWED US SLIGHTLY R OF COURSE AND THE CAPT BEGAN TO CORRECT, THEN WE BROKE OUT. THIS WAS WHEN TWR ASKED IF WE HAD THE PER COURSE AND WERE FLYING IT. I REPLIED CORRECTING, AND THEN TWR DIRECTED A GAR, HDG 180 DEGS, ALT 2000 FT, CONTACT APCH. WE APPLIED MISSED APCH PROC AND WERE VECTORED AROUND FOR ANOTHER UNEVENTFUL APCH AND LNDG. LESSONS LEARNED, XCHKS ARE DIFFERENT DUE TO MANUALLY ENTERING DATA AND COMPUTERS LOCKED UP. LACK OF FAMILIARITY WITH MANUAL ENTERY AND FLYING ILS PROCS. WE SHOULD HAVE INFORMED ATC OF OUR EQUIP DEGRADE SO CLOSER MONITORING COULD HAVE BEEN ACCOMPLISHED. SUPPLEMENTAL INFO FROM ACN 543856: SOME MINOR CONFUSION MAKING SURE RADIOS WERE CORRECTLY SETUP. DRIFTED N OF COURSE. TWR INITIATED GAR. NORMAL APCH AND LNDG FOLLOWED. MOSTLY VISUAL.

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.