Narrative:

Captain was PF and I was first officer and PNF on ILS runway 36R approach at mem. Approach cleared us to descend to 2000 ft and maintain a 330 degree heading until established on the localizer and cleared us for the approach. The captain selected approach mode and he was LOC1/GS armed while I was LOC2/GS armed. Our respective navigation displays both correctly showed the 358 degree inbound localizer course and the automatic-identify for the localizer. I also received a correct morse code identify for the localizer. Approach control handed us off to mem tower. Approximately abeam hadan fix; my LOC2 captured while his LOC1 still showed a left deflection. I compared my localizer alignment with the FMS overlay and showed we were centered on the localizer. As we flew through the runway 36R localizer; the captain's LOC1 still showed a left deflection and did not capture. I notified him of the deviation left of course and tower queried us about our alignment. I told tower we were getting established and then told the captain to come right. His LOC1 indication still showed a left deflection; he clicked off the autoplt; removed the flight director; and hand-flew the aircraft back to the correct course. Tower queried us again to ensure we were lining up for runway 36R and not runway 36L. I responded that we were set up for runway 36R. The captain and I agreed that his side was showing incorrect LOC1 data as he showed full-scale left deflection while LOC2 was nearly centered and consistent with the FMS course overlay. At this point; we xferred controls and now I was the PF. I hand-flew the approach on LOC2 raw data. At approximately mcghe FAF the captain queried tower on our localizer alignment and they stated we were on course. My LOC2 continued to show us aligned while the captain's LOC1 showed full-scale left deflection. Shortly before we broke out of the clouds; the captain again asked tower if we appeared to be on course and they responded that we were. As we broke out of the clouds at about 300 ft AGL; we were aligned right of runway 36R. I then observed a yellow localizer flag on my HSI. At about the same time; we received an 'EFIS comp mon' caution indicating our respective pfd headings were misaligned. The captain saw the runway 36R approach lights to our left; took control of the aircraft and landed the aircraft safely. Once at the gate; our company's avionics technician stated this aircraft had a history of localizer problems on approachs. In looking back on the event; one thing we could have done better was after xferring control of the aircraft; I should have instructed the captain to re-select approach mode which would reactivate the flight director. Then we could have activated the autoplt to give us a better idea of the significance of the problem by both of us monitoring the various indications. Had the LOC2 indications been correct; we could have eased our workload from the FAF to landing (which appeared to be the case at least until short final). Otherwise; had we seen the LOC2 data was also incorrect compared with the FMS course overlay; we would have removed the automation and conducted a missed approach. As it was; hand-flying a raw data approach worked out successfully.

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Original NASA ASRS Text

Title: CL600 CRJ FLT CREW HAS A TRACK AND HDG DEV DURING APCH TO MEM DUE TO ACFT EQUIP PROBS.

Narrative: CAPT WAS PF AND I WAS FO AND PNF ON ILS RWY 36R APCH AT MEM. APCH CLRED US TO DSND TO 2000 FT AND MAINTAIN A 330 DEG HDG UNTIL ESTABLISHED ON THE LOC AND CLRED US FOR THE APCH. THE CAPT SELECTED APCH MODE AND HE WAS LOC1/GS ARMED WHILE I WAS LOC2/GS ARMED. OUR RESPECTIVE NAV DISPLAYS BOTH CORRECTLY SHOWED THE 358 DEG INBOUND LOC COURSE AND THE AUTO-IDENT FOR THE LOC. I ALSO RECEIVED A CORRECT MORSE CODE IDENT FOR THE LOC. APCH CTL HANDED US OFF TO MEM TWR. APPROX ABEAM HADAN FIX; MY LOC2 CAPTURED WHILE HIS LOC1 STILL SHOWED A L DEFLECTION. I COMPARED MY LOC ALIGNMENT WITH THE FMS OVERLAY AND SHOWED WE WERE CTRED ON THE LOC. AS WE FLEW THROUGH THE RWY 36R LOC; THE CAPT'S LOC1 STILL SHOWED A L DEFLECTION AND DID NOT CAPTURE. I NOTIFIED HIM OF THE DEV L OF COURSE AND TWR QUERIED US ABOUT OUR ALIGNMENT. I TOLD TWR WE WERE GETTING ESTABLISHED AND THEN TOLD THE CAPT TO COME R. HIS LOC1 INDICATION STILL SHOWED A L DEFLECTION; HE CLICKED OFF THE AUTOPLT; REMOVED THE FLT DIRECTOR; AND HAND-FLEW THE ACFT BACK TO THE CORRECT COURSE. TWR QUERIED US AGAIN TO ENSURE WE WERE LINING UP FOR RWY 36R AND NOT RWY 36L. I RESPONDED THAT WE WERE SET UP FOR RWY 36R. THE CAPT AND I AGREED THAT HIS SIDE WAS SHOWING INCORRECT LOC1 DATA AS HE SHOWED FULL-SCALE L DEFLECTION WHILE LOC2 WAS NEARLY CTRED AND CONSISTENT WITH THE FMS COURSE OVERLAY. AT THIS POINT; WE XFERRED CTLS AND NOW I WAS THE PF. I HAND-FLEW THE APCH ON LOC2 RAW DATA. AT APPROX MCGHE FAF THE CAPT QUERIED TWR ON OUR LOC ALIGNMENT AND THEY STATED WE WERE ON COURSE. MY LOC2 CONTINUED TO SHOW US ALIGNED WHILE THE CAPT'S LOC1 SHOWED FULL-SCALE L DEFLECTION. SHORTLY BEFORE WE BROKE OUT OF THE CLOUDS; THE CAPT AGAIN ASKED TWR IF WE APPEARED TO BE ON COURSE AND THEY RESPONDED THAT WE WERE. AS WE BROKE OUT OF THE CLOUDS AT ABOUT 300 FT AGL; WE WERE ALIGNED R OF RWY 36R. I THEN OBSERVED A YELLOW LOC FLAG ON MY HSI. AT ABOUT THE SAME TIME; WE RECEIVED AN 'EFIS COMP MON' CAUTION INDICATING OUR RESPECTIVE PFD HDGS WERE MISALIGNED. THE CAPT SAW THE RWY 36R APCH LIGHTS TO OUR L; TOOK CTL OF THE ACFT AND LANDED THE ACFT SAFELY. ONCE AT THE GATE; OUR COMPANY'S AVIONICS TECHNICIAN STATED THIS ACFT HAD A HISTORY OF LOC PROBS ON APCHS. IN LOOKING BACK ON THE EVENT; ONE THING WE COULD HAVE DONE BETTER WAS AFTER XFERRING CTL OF THE ACFT; I SHOULD HAVE INSTRUCTED THE CAPT TO RE-SELECT APCH MODE WHICH WOULD REACTIVATE THE FLT DIRECTOR. THEN WE COULD HAVE ACTIVATED THE AUTOPLT TO GIVE US A BETTER IDEA OF THE SIGNIFICANCE OF THE PROB BY BOTH OF US MONITORING THE VARIOUS INDICATIONS. HAD THE LOC2 INDICATIONS BEEN CORRECT; WE COULD HAVE EASED OUR WORKLOAD FROM THE FAF TO LNDG (WHICH APPEARED TO BE THE CASE AT LEAST UNTIL SHORT FINAL). OTHERWISE; HAD WE SEEN THE LOC2 DATA WAS ALSO INCORRECT COMPARED WITH THE FMS COURSE OVERLAY; WE WOULD HAVE REMOVED THE AUTOMATION AND CONDUCTED A MISSED APCH. AS IT WAS; HAND-FLYING A RAW DATA APCH WORKED OUT SUCCESSFULLY.

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.