THE CAPT OF A DORNIER 328 LOST NOSEWHEEL STEERING CAPABILITY DURING TAXI WHILE TURNING. ELECTRICAL SYS DISTRIBUTION DESIGN AND BATTERY MAINT WERE DETERMINED TO BE THE CAUSE OF THE FAILURE.

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I WAS PIC (PF). JUST CLRING RWY 17 AT AZO. FO (PNF) STARTED APU AS PER NORMAL OPS. NOSEWHEEL STEERING FAILED AT STARTER ENGAGEMENT; CAUSING US TO VERY NEARLY RUN OFF THE PAVEMENT. THROUGH TALKING TO OTHERS; I HAVE FOUND THIS TO HAVE HAPPENED TO SEVERAL OTHER CREWS. THIS IS A BRAND NEW; STATE OF THE ART; HIGHLY AUTOMATED ACFT; BUT IT SEEMS TO HAVE SOME LOGIC AND FAILURE QUIRKS THAT SLIPPED AT CERTIFICATION. ONE OF OUR CAPTS PUT IT BEST BY STATING; 'IF WE EVER LOSE A DORNIER; THE LAST THING ON THE CVR WILL BE 'NOW WHY DO YOU SUPPOSE IT DID THAT?' CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATES THAT THIS NEWLY CERTIFICATED ACFT HAS A MULTITUDE OF PROBS; SOME OF THEM ARE CURRENTLY RECEIVING ATTN FROM INVOLVED MANUFACTURERS. RPTR IS UNCERTAIN REGARDING ELECTRICAL DISTRIBUTION SYS STATUS; BUT RPTR'S COMPANY HAS TAKEN ACTION PER CHIEF PLT'S INFLUENCE. IT WAS DETERMINED THAT THE NOSEWHEEL STEERING FAILURE (COMMON PROB) WAS DIRECTLY RELATED TO THE BATTERY PWR CTL UNIT (BPCU); AND SPECIFICALLY TO NICAD BATTERY MAINT. APPARENTLY; POOR BATTERY MAINT (DEEP CYCLING) WAS AFFECTING BATTERY CAPACITY; AND WHEN THE BPCU SENSES A DROP IN VOLTAGE; IT ISOLATES THE BATTERIES FROM THE MAIN BUSES; LEAVING ONLY HOT BATTERY BUS ITEMS POWERED. THIS SCENARIO BEGAN DURING TAXI THROUGH A 90 DEG TURN. THE FO WAS STARTING THE APU WHICH CAUSED ENOUGH OF A DROP IN VOLTAGE FOR THE BATTERIES TO BE ISOLATED BY THE BPCU. NOSEWHEEL STEERING; POWERED BY A NON-ESSENTIAL BUS; FAILED AS A RESULT. THE NOSEWHEEL WENT TO CENTERING; AND THE CAPT WAS FORCED TO JUMP ON DIFFERENTIAL STEERING (BRAKING) IN ORDER TO REGAIN ACFT CTL. SINCE THE RPTR HAS BEEN FLYING THE DORNIER 328-100 HE HAS EXPERIENCED A SHATTERED WINDSHIELD; BLEED FAILURE (BOTH); EFIS COURSE NEEDLE 'FREEZING;' LNDG GEAR EXTENSION FAIL CAUSED BY FAIRING AND FUSELAGE BUCKLING DIFFERENCES; AND BOGUS EICAS MESSAGES. HE HAS RECEIVED MESSAGES THAT DON'T EVEN APPLY TO HIS ACFT; SUCH AS 'GND SPOILERS ARMED;' 'HEADS- UP DISPLAY INOP;' AND HYD SYS PROBS.