Narrative:

En route at FL390 from jfk to las, the left hydraulic system began losing fluid. We elected to land at our destination in las vegas and discussed the problem with dispatch and maintenance control. The flight attendants were briefed that a normal landing would be planned and that emergency equipment would be standing by as a precaution. The passenger were briefed concerning the malfunction and informed that a normal landing was planned with emergency equipment standing by as a precaution. We declared an emergency with ATC and received priority handling to the airport. The standpipe fluid/ptu function did not supply enough hydraulic pressure, so the flaps were lowered by alternate means. The gear extended normally, but the gear doors remained down. Since nosewheel steering was not available, we stopped on the runway and were towed to the gate. The landing was uneventful, all checklists were accomplished properly, and the flight arrived safely in las vegas. As previously briefed, the passenger did not brace for landing. Apparently, company ground personnel assumed that it was a 'planned emergency' in which passenger should brace for landing. Although this was confusing for operations personnel, the flight attendants and passenger were well informed as to our planned normal landing. Callback conversation with reporter revealed the following information: the reporter stated the loss of #1 hydraulic system pressure and quantity was caused by a chaffed hydraulic line on #1 engine right side. The reporter said the line was poorly routed and clamped too close to an engine component and rubbed right through.

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Original NASA ASRS Text

Title: A B757-200 IN CRUISE AT FL390 DECLARED AN EMER DUE TO LOSS OF THE L HYD SYS PRESSURE AND QUANTITY. CAUSED BY A CHAFFED ENG HYD LINE.

Narrative: ENRTE AT FL390 FROM JFK TO LAS, THE L HYD SYS BEGAN LOSING FLUID. WE ELECTED TO LAND AT OUR DEST IN LAS VEGAS AND DISCUSSED THE PROB WITH DISPATCH AND MAINT CTL. THE FLT ATTENDANTS WERE BRIEFED THAT A NORMAL LNDG WOULD BE PLANNED AND THAT EMER EQUIP WOULD BE STANDING BY AS A PRECAUTION. THE PAX WERE BRIEFED CONCERNING THE MALFUNCTION AND INFORMED THAT A NORMAL LNDG WAS PLANNED WITH EMER EQUIP STANDING BY AS A PRECAUTION. WE DECLARED AN EMER WITH ATC AND RECEIVED PRIORITY HANDLING TO THE ARPT. THE STANDPIPE FLUID/PTU FUNCTION DID NOT SUPPLY ENOUGH HYD PRESSURE, SO THE FLAPS WERE LOWERED BY ALTERNATE MEANS. THE GEAR EXTENDED NORMALLY, BUT THE GEAR DOORS REMAINED DOWN. SINCE NOSEWHEEL STEERING WAS NOT AVAILABLE, WE STOPPED ON THE RWY AND WERE TOWED TO THE GATE. THE LNDG WAS UNEVENTFUL, ALL CHKLISTS WERE ACCOMPLISHED PROPERLY, AND THE FLT ARRIVED SAFELY IN LAS VEGAS. AS PREVIOUSLY BRIEFED, THE PAX DID NOT BRACE FOR LNDG. APPARENTLY, COMPANY GND PERSONNEL ASSUMED THAT IT WAS A 'PLANNED EMER' IN WHICH PAX SHOULD BRACE FOR LNDG. ALTHOUGH THIS WAS CONFUSING FOR OPS PERSONNEL, THE FLT ATTENDANTS AND PAX WERE WELL INFORMED AS TO OUR PLANNED NORMAL LNDG. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE LOSS OF #1 HYD SYS PRESSURE AND QUANTITY WAS CAUSED BY A CHAFFED HYD LINE ON #1 ENG R SIDE. THE RPTR SAID THE LINE WAS POORLY ROUTED AND CLAMPED TOO CLOSE TO AN ENG COMPONENT AND RUBBED RIGHT THROUGH.

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.