Narrative:

Hydraulic failure on short final on runway 4L bos during high workload visual approach. Unable to go around due to aircraft confign. Memory item checklist complete. Normal landing, aircraft taxied clear of active. While captain ran appropriate abnormal checklist and talk with local company operations, first officer talked with ground control. Checklist interrupted by request from ground control to move aircraft clear of taxiway. Aircraft was taxied onto ramp. When parking, parking brake failed and during shutdown aircraft jumped chocks and struck company maintenance truck. The checklists for hydraulic problems for this aircraft are multi-page and multi-part with many 'if' and 'and/or' branches. This causes much confusion when attempting to sort problems via checklist. Callback conversation with reporter revealed the following information: the reporter stated the aircraft was a saab 340B and the hydraulic pressure and quantity loss was caused by a failed union coupling in the pressure line from the electric pump to the main accumulator. The reporter said braking was available from the pressure in the brake accumulators but is limited. The reporter said the aircraft incurred damage to the left propeller.

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Original NASA ASRS Text

Title: 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.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.