AN SF340B FLYING IN ZME; TN; AIRSPACE; LOSES HYD PRESSURE. FLC IS ABLE TO SAFELY LAND AT DEST; MEM; TN.

Narrative

WHILE IN CRUISE FLT FROM MOBILE; AL; TO MEMPHIS; TN; IT WAS NOTICED THAT THE HYD PUMP BEGAN TO RUN CONTINUOUSLY. OBSERVING THE HYD PANEL; THE HYD QUANTITY IN THE MAIN RESERVOIR WAS DECREASING RAPIDLY. THE HYD PUMP WAS THEN IMMEDIATELY SHUT OFF. AT THIS POINT THERE WAS VERY LITTLE QUANTITY REMAINING IN THE MAIN RESERVOIR. (ALL OTHER INDICATIONS APPEARED NORMAL.) AFTER COMPLETING THE APPROPRIATE CHKLISTS; WE CONTACTED OPS AND MAINT. AFTER DISCUSSING OUR MANY OPTIONS; WE DETERMINED THAT THE FLT WOULD CONTINUE TO MEM. NOT KNOWING THE EXTENT OF OUR PROB; WE PROCEEDED TO LOWER THE LNDG GEAR AND AS A PRECAUTIONARY MEASURE; DECLARE AN EMER. WE RECEIVED DIRECT ROUTING TO MEM WHERE THE CRASH; FIRE; AND RESCUE VEHICLES WERE STANDING BY. THE LNDG PROCEEDED UNEVENTFUL AND BRAKING ACTION WAS NORMAL. AS THE ACFT DECELERATED TO A STOP; THE NOSEWHEEL CASTERED 90 DEGS TO THE L DISABLING THE ACFT ON THE RWY. THE PAX DEPLANED USING THE AIRSTAIRS AND THEN THEY WERE ESCORTED TO THE TERMINAL VIA BUS. THERE WERE NO INJURIES AS A RESULT OF THIS INCIDENT. AFTER MAINT COMPLETED AN INSPECTION; IT WAS DETERMINED THAT A HYD LINE RUPTURED JUST OUTSIDE THE PUMP. (AS PRESSURE/FLUID DECREASED IN THE RESERVOIR THE PUMP TURNED ON AND BEGAN TO PUMP ALL OF THE FLUID OVERBOARD.) THE GEAR WAS LOWERED USING THE HAND PUMP EXHIBITING A NORMAL 3 GREEN INDICATION. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT ALL EMER PROCS WENT WELL AND ALL THE HELP FROM ARTCC WAS PERFECT. THE RPTR JUST HAPPENED TO GLANCE AT THE HYD PUMP LIGHT AND NOTICED IT WAS ON CONTINUOUSLY WHILE IN CRUISE. IT WOULD NORMALLY BE OFF. THIS MEANT THE ELECTRIC HYD PUMP WAS PUMPING FLUID SOMEWHERE. THE ELECTRIC PUMP WAS PUMPING FLUID OVERBOARD DUE TO A BAD HOSE FITTING OR RUPTURE IN THE HYD LINE. THE FLC PREPARED FOR WHAT MIGHT BE LOST WITH NO HYD PRESSURE. WHEN THE LNDG GEAR WAS LOWERED; ALL 3 LNDG GEAR LEFT THE WHEEL WELL BECAUSE THE ACCUMULATORS HAD STORED ENOUGH PRESSURE TO GET THE LNDG GEAR DOWN AND EXTEND THE FLAPS. WHEN LNDG; THE BRAKES WORKED NORMALLY UNTIL THE ACFT CAME TO A STOP. THEN; WITH ALL HYDS LOST THE NOSEWHEEL CASTERED 90 DEGS AND THERE WAS NO PRESSURE TO MOVE THE NOSEWHEEL FOR TAXI PURPOSES. ACFT HAD TO BE TOWED TO THE GATE. PAX WERE EVACUATED ON THE RWY WITH NO INJURIES.