HDG TRACK DEV ON IAP LOC BACK COURSE APCH.

Narrative

ON SEP/XX/94; WHILE ENRTE FROM BIL TO SFF; MY HUSBAND REQUESTED A 'COMFORT STOP.' AS WE WERE 10 NM W OF MSO; I ELECTED TO RETURN THERE. AFTER TAXIING TO THE RAMP AND SHUTTING DOWN; MY HUSBAND EXPERIENCED A PERIOD OF UNCONSCIOUSNESS. THIS LED TO HIS HOSPITALIZATION IN MISSOULA AND TESTS WHICH INDICATED HE REQUIRED CORONARY BYPASS SURGERY. HE ELECTED TO HAVE THIS DONE IN THE SEATTLE AREA WHERE WE RESIDE. HE RETURNED TO SEATTLE VIA COMMERCIAL AIR ON SEP/XX/94. AFTER SEEING HIM OFF; I DEPARTED FOR BFI. I WAS AWARE THAT I WAS UNDER MORE THAN NORMAL STRESS AND FILED IFR ALTHOUGH THE WX WAS CLR OVER THE ENTIRE AREA. I ALSO VERBALIZED EACH CHKLIST; FREQ AND NAV ITEM TO MYSELF; WITH 1 EXCEPTION. ON ARRIVING IN THE SEATTLE APCH AREA I ELECTED TO FLY THE LOC BC TO RWY 31L; BFI. I HAD BEEN CLRED FOR THE APCH AND HAD INTERCEPTED THE LOC. I NOTED A SMALL DEV OF THE CDI NEEDLE TO THE L AND CORRECTED -- TO THE L. AS THE NEEDLE DEFLECTED FULLY; I POSITIVELY IDENTED THE RWY; CORRECTED MY POS AND REALIZED WHAT MY ERROR HAD BEEN. I COULD HAVE DONE A VISUAL APCH BUT ELECTED AT THE LAST MIN TO DO THE LOC BACK COURSE. AS 3 ARPTS ARE IN VERY CLOSE PROX I DESIRED TO BE PRECISE IN MY APCH. UNFORTUNATELY I WAS MUCH LESS PRECISE THAN DESIRED. I TRULY BELIEVE THE ADDED STRESS OF MY HUSBANDS SIT WAS A PRIMARY FACTOR IN MY NEGLECTING TO THOROUGHLY 'BRIEF' MYSELF ON THE APCH. I KNEW I WAS CLOSE TO HOME AND QUITE LIKELY LET DOWN MY DEFENSES.