AN ATP SINGLE JET PLT HAS PROBS WITH HIS MISSED APCH PROC WHEN LOSING HIS ADI AND HAVING TO FLY 'PARTIAL PANEL' DURING THE MISSED APCH. RADAR ADVISORIES PROVIDED BY ZJX; FL.

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LOCALIZED AREA OF MODERATE/HVY RAIN NEAR AND OVER DEST ARPT. CTR CTLR RPTED 'IT'S ONLY HVY RAIN; THERE'S NOTHING IN IT.' THIS WAS CONSISTENT WITH THE PATTERN OF THE PREVIOUS DAY OR 2. CARRIED OUT NORMAL VOR APCH USING AUTOPLT/FLT DIRECTOR. AT MISSED APCH; BEGAN A CLB ON AUTOPLT. ENCOUNTERED VERY HVY RAIN; MODERATE TURB. AT APPROX 700 FT MSL 9250 FT ABOVE MINIMUMS) ADI FAILED WITH LOSS OF ALL AUTOPLT/FLT DIRECTOR FUNCTIONS. PLT HAD DIFFICULTY MAINTAINING PRECISE CTL OVER ACFT USING BACKUP INSTS DUE TO TURB AND LOSS OF POS AND ALT GUIDANCE. CONTRIBUTING FACTORS: 1) BACKUP INSTS NOT SET UP FOR MISSED APCH. 2) PLT DID NOT STUDY AND PREPARE ADEQUATELY FOR MISSED APCH. 3) LACK OF SITUATIONAL AWARENESS WHEN TALKING WITH CTLR DUE TO LACK OF FAMILIARITY WITH NEARBY LANDMARKS; FIXES AND WAYPOINTS. CORRECTIVE ACTIONS: TRAINING SHOULD INCLUDE SETTING UP BACKUP NAV INDICATORS FOR APCH/MISSED APCH IN ANTICIPATION OF PRIMARY ADI/HSI FAILURE. PLTS NEED TO THOROUGHLY MEMORIZE AND SET UP MISSED APCH BECAUSE AN EMER OR EQUIP FAILURE DOES NOT LEAVE TIME TO READ IT WHILE EXECUTING. POOR SOFTWARE DESIGN OF KLN90B GPS CONTRIBUTES TO DIFFICULTIES WITH SITUATIONAL AWARENESS.