Narrative:

Just prior to TOD, first officer at controls, autoplt 'B' tripped off. We had both 'B' hydraulic pumps fail and #1 engine 'a' hydraulic pump fail. Selected 'a' autoplt. 30 seconds later, 'a' autoplt tripped off. Both engine hydraulic pumps 'a' and 'B' failed and both 'B' hydraulic pumps started working again. We had no loss of hydraulic quantity just 'a' system pressure failure. We reset the engine hydraulic shutoff valve circuit breakers and engine had switches, no effect. Captain took control of the aircraft and first officer ran loss of 'a' system hydraulic checklist. This checklist worked very well. It made our manual gear and alternate flaps extension process easier. We landed with 15 degrees flaps and medium autobrakes and stopped on the runway. The fire chief inspected the aircraft and found no leaks or fires. The aircraft was towed to gate. Callback conversation with reporter revealed the following information: the reporter stated the reported fix was replacement of the hydraulic filters and the cockpit overhead hydraulic panel which contained the hydraulic pump control switches. The reporter said the aircraft was run and all hydraulic pumps operated normally.

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Original NASA ASRS Text

Title: A B737-200 IN CRUISE AT FL330 DECLARED AN EMER DUE TO LOSS OF #1 ENG DRIVEN HYD PUMP PRESSURE.

Narrative: JUST PRIOR TO TOD, FO AT CTLS, AUTOPLT 'B' TRIPPED OFF. WE HAD BOTH 'B' HYD PUMPS FAIL AND #1 ENG 'A' HYD PUMP FAIL. SELECTED 'A' AUTOPLT. 30 SECONDS LATER, 'A' AUTOPLT TRIPPED OFF. BOTH ENG HYD PUMPS 'A' AND 'B' FAILED AND BOTH 'B' HYD PUMPS STARTED WORKING AGAIN. WE HAD NO LOSS OF HYD QUANTITY JUST 'A' SYS PRESSURE FAILURE. WE RESET THE ENG HYD SHUTOFF VALVE CIRCUIT BREAKERS AND ENG HAD SWITCHES, NO EFFECT. CAPT TOOK CTL OF THE ACFT AND FO RAN LOSS OF 'A' SYS HYD CHKLIST. THIS CHKLIST WORKED VERY WELL. IT MADE OUR MANUAL GEAR AND ALTERNATE FLAPS EXTENSION PROCESS EASIER. WE LANDED WITH 15 DEGS FLAPS AND MEDIUM AUTOBRAKES AND STOPPED ON THE RWY. THE FIRE CHIEF INSPECTED THE ACFT AND FOUND NO LEAKS OR FIRES. THE ACFT WAS TOWED TO GATE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE RPTED FIX WAS REPLACEMENT OF THE HYD FILTERS AND THE COCKPIT OVERHEAD HYD PANEL WHICH CONTAINED THE HYD PUMP CTL SWITCHES. THE RPTR SAID THE ACFT WAS RUN AND ALL HYD PUMPS OPERATED NORMALLY.

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.