A319 crew has IRU malfunction on arrival to lax with many secondary malfunctions.

Attributes
ACN	711718
Time
Date	200609
Local Time Of Day	1801 To 2400
Place
Locale Reference	navaid : smo.vor
State Reference	CA
Altitude	msl single value : 10000
Aircraft 1
Controlling Facilities	tracon : sct.tracon
Operator	common carrier : air carrier
Make Model Name	A319
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	arrival star : sadde6
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 210 flight time total : 20000 flight time type : 6400
ASRS Report	711718
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted none taken : insufficient time
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

Over smo VOR on SADDE6 (STAR) to lax; I notice #1 IRU position was wrong on captain's navigation display. Image of aircraft position shows south of lax airport and supposed to be north. #2 IRU at that moment it was the only one with correct position. Checking the position monitor on mcdu for IRU #1 with IRU #2 and mixed position all with different indication and at least 5.0 mi apart. The same time on the scratchpad display FMGC1/FMGC2 position disagree. At 900 ft on the visual approach egpws caution terrain; too low terrain; and on both navigation displays and the aircraft was on missed approach phase on FMGC. I hard-tuned the ILS runway 24R for raw data as back up. At 600-500 ft we lost the destination airport (lax) on both FMGC's. WX at lax was 7 mi visibility clear. We continue the approach and land safe at runway 24R at lax. After landing at lax we reenter the destination airport lax on FMGC; and the position indicate aircraft was 7 mi south of lax. No IRU fault or any other ECAM on the approach. The autoplt and autothrottle was off since we passed the smo VOR.

Original NASA ASRS Text

Title: A319 CREW HAS IRU MALFUNCTION ON ARR TO LAX WITH MANY SECONDARY MALFUNCTIONS.

Narrative: OVER SMO VOR ON SADDE6 (STAR) TO LAX; I NOTICE #1 IRU POS WAS WRONG ON CAPT'S NAV DISPLAY. IMAGE OF ACFT POS SHOWS S OF LAX ARPT AND SUPPOSED TO BE N. #2 IRU AT THAT MOMENT IT WAS THE ONLY ONE WITH CORRECT POS. CHKING THE POS MONITOR ON MCDU FOR IRU #1 WITH IRU #2 AND MIXED POS ALL WITH DIFFERENT INDICATION AND AT LEAST 5.0 MI APART. THE SAME TIME ON THE SCRATCHPAD DISPLAY FMGC1/FMGC2 POS DISAGREE. AT 900 FT ON THE VISUAL APCH EGPWS CAUTION TERRAIN; TOO LOW TERRAIN; AND ON BOTH NAV DISPLAYS AND THE ACFT WAS ON MISSED APCH PHASE ON FMGC. I HARD-TUNED THE ILS RWY 24R FOR RAW DATA AS BACK UP. AT 600-500 FT WE LOST THE DEST ARPT (LAX) ON BOTH FMGC'S. WX AT LAX WAS 7 MI VISIBILITY CLR. WE CONTINUE THE APCH AND LAND SAFE AT RWY 24R AT LAX. AFTER LNDG AT LAX WE REENTER THE DEST ARPT LAX ON FMGC; AND THE POS INDICATE ACFT WAS 7 MI S OF LAX. NO IRU FAULT OR ANY OTHER ECAM ON THE APCH. THE AUTOPLT AND AUTOTHROTTLE WAS OFF SINCE WE PASSED THE SMO VOR.

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.