Narrative:

In cruise at FL330 approximately 30 mi west of grr VOR, master caution light illuminated, looked up and saw 'left hydraulic pres low' annuncator light illuminated, checked hydraulic control panel and saw left system hydraulic pressure at zero and the left hydraulic fluid qty needle moving to full maximum scale. Contacted dispatch and maintenance controller and followed cockpit operating manual (communication) for 'left hydraulic press low light illum.' with concurrence from dispatch and maintenance controller continued flight from approximately djb VOR to phl with left hydraulic system inoperative. In descent phase of flight approaching jsf VOR at approximately FL230 saw right hydraulic fluid qty needle going to zero. Followed communication procedure for 'hydraulic fluid qty loss' of the right hydraulic system. Set up for no slat, no flap landing into phl with both hydraulic systems inoperative, with fluid qty indicating zero on the right side but still indicating hydraulic press on the right hydraulic, received concurence from maintenance controller to extend flap and slats, lnded with slats partial extended and flaps 15 degrees, using brake accumulator press and there was no nosewheel steering so aircraft had to be towed off runway. Superb job by ATC in handling aircraft, afrr at phl also did a great job, watched as one problem became compounded by the loss of another system. Not the way things are supposed to happen. Luckly all backup systems worked as advertised, and the flight ended uneventfully. Callback conversation with reporter revealed the following information: the reporter stated the cause of the left hydraulic system was failure of the engine driven pump. The reporter said the right system hydraulic failure was a failed press line, but the exact location and failure mode is unknown. The reporter said a two main hydraulic system loss is not supposed to happen. The reporter stated the aircraft without hydraulics flew as advertised in manual reversion.

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Original NASA ASRS Text

Title: A DC9-30 IN CRUISE AT FL 330 EXPERIENCES LOSS OF L HYD SYS DUE TO FAILED ENG DRIVEN PUMP LATER IN FLT R HYD SYS LOST DUE TO FAILED PRESS LINE.

Narrative: IN CRUISE AT FL330 APPROX 30 MI W OF GRR VOR, MASTER CAUTION LIGHT ILLUMINATED, LOOKED UP AND SAW 'L HYD PRES LOW' ANNUNCATOR LIGHT ILLUMINATED, CHECKED HYD CTL PANEL AND SAW LEFT SYSTEM HYD PRESSURE AT ZERO AND THE LEFT HYD FLUID QTY NEEDLE MOVING TO FULL MAX SCALE. CONTACTED DISPATCH AND MAINT CTLR AND FOLLOWED COCKPIT OPERATING MANUAL (COM) FOR 'L HYD PRESS LOW LIGHT ILLUM.' WITH CONCURRENCE FROM DISPATCH AND MAINT CTLR CONTINUED FLIGHT FROM APPROX DJB VOR TO PHL WITH LEFT HYD SYSTEM INOP. IN DSCNT PHASE OF FLIGHT APCHING JSF VOR AT APPROX FL230 SAW RIGHT HYD FLUID QTY NEEDLE GOING TO ZERO. FOLLOWED COM PROC FOR 'HYD FLUID QTY LOSS' OF THE R HYD SYSTEM. SET UP FOR NO SLAT, NO FLAP LNDG INTO PHL WITH BOTH HYD SYSTEMS INOP, WITH FLUID QTY INDICATING ZERO ON THE R SIDE BUT STILL INDICATING HYD PRESS ON THE R HYD, RECEIVED CONCURENCE FROM MAINT CTLR TO EXTEND FLAP AND SLATS, LNDED WITH SLATS PARTIAL EXTENDED AND FLAPS 15 DEGS, USING BRAKE ACCUMULATOR PRESS AND THERE WAS NO NOSEWHEEL STEERING SO ACFT HAD TO BE TOWED OFF RWY. SUPERB JOB BY ATC IN HANDLING ACFT, AFRR AT PHL ALSO DID A GREAT JOB, WATCHED AS ONE PROBLEM BECAME COMPOUNDED BY THE LOSS OF ANOTHER SYSTEM. NOT THE WAY THINGS ARE SUPPOSED TO HAPPEN. LUCKLY ALL BACKUP SYSTEMS WORKED AS ADVERTISED, AND THE FLIGHT ENDED UNEVENTFULLY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE CAUSE OF THE LEFT HYD SYS WAS FAILURE OF THE ENG DRIVEN PUMP. THE RPTR SAID THE R SYS HYD FAILURE WAS A FAILED PRESS LINE, BUT THE EXACT LOCATION AND FAILURE MODE IS UNKNOWN. THE RPTR SAID A TWO MAIN HYD SYS LOSS IS NOT SUPPOSED TO HAPPEN. THE RPTR STATED THE ACFT WITHOUT HYDRAULICS FLEW AS ADVERTISED IN MANUAL REVERSION.

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.