A SAAB 340B WHILE TAXIING ON TO GATE AFTER COMPLETE LOSS OF MAIN SYS HYD PRESSURE AND QUANTITY THE ACFT JUMPED THE CHOCKS AND STRUCK A PARKED VEHICLE.

Narrative

HYD FAILURE ON SHORT FINAL ON RWY 4L BOS DURING HIGH WORKLOAD VISUAL APCH. UNABLE TO GAR DUE TO ACFT CONFIGN. MEMORY ITEM CHKLIST COMPLETE. NORMAL LNDG; ACFT TAXIED CLR OF ACTIVE. WHILE CAPT RAN APPROPRIATE ABNORMAL CHKLIST AND TALK WITH LCL COMPANY OPS; FO TALKED WITH GND CTL. CHKLIST INTERRUPTED BY REQUEST FROM GND CTL TO MOVE ACFT CLR OF TXWY. ACFT WAS TAXIED ONTO RAMP. WHEN PARKING; PARKING BRAKE FAILED AND DURING SHUTDOWN ACFT JUMPED CHOCKS AND STRUCK COMPANY MAINT TRUCK. THE CHKLISTS FOR HYD PROBS FOR THIS ACFT ARE MULTI-PAGE AND MULTI-PART WITH MANY 'IF' AND 'AND/OR' BRANCHES. THIS CAUSES MUCH CONFUSION WHEN ATTEMPTING TO SORT PROBS VIA CHKLIST. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ACFT WAS A SAAB 340B AND THE HYD PRESSURE AND QUANTITY LOSS WAS CAUSED BY A FAILED UNION COUPLING IN THE PRESSURE LINE FROM THE ELECTRIC PUMP TO THE MAIN ACCUMULATOR. THE RPTR SAID BRAKING WAS AVAILABLE FROM THE PRESSURE IN THE BRAKE ACCUMULATORS BUT IS LIMITED. THE RPTR SAID THE ACFT INCURRED DAMAGE TO THE L PROP.