Narrative:

Cleared to FL240 by ZZZ center. Began descent. Shortly thereafter; EICAS displayed 'center hydraulic quantity.' checked status page; center quantity was 0.33. Looking on annunciator panel; 'reservoir' illuminated for center hydraulic system. First officer began QRH procedures. Declared emergency with center. Asked by ATC whether we needed any assistance. Said not at this time. Completed QRH procedures. Further on descent (below 10000 ft) tried extending speed brakes and received 'spoilers' EICAS and corresponding annunciator light. Further on approach; received 'right yaw damper' EICAS and corresponding annunciator light. Felt no degradation of handling of aircraft. Landed aircraft uneventfully. Only procedure I forgot to accomplish; was notifying #1 flight attendant of emergency -- tunnel locked on flying aircraft.

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Original NASA ASRS Text

Title: B757-200 LOST HYD FLUID IN CENTER HYD SYSTEM DURING DESCENT. EMER WAS DECLARED; AND LNDG ACCOMPLISHED AT DEST ARPT.

Narrative: CLRED TO FL240 BY ZZZ CTR. BEGAN DSCNT. SHORTLY THEREAFTER; EICAS DISPLAYED 'CTR HYD QUANTITY.' CHKED STATUS PAGE; CTR QUANTITY WAS 0.33. LOOKING ON ANNUNCIATOR PANEL; 'RESERVOIR' ILLUMINATED FOR CTR HYD SYS. FO BEGAN QRH PROCS. DECLARED EMER WITH CTR. ASKED BY ATC WHETHER WE NEEDED ANY ASSISTANCE. SAID NOT AT THIS TIME. COMPLETED QRH PROCS. FURTHER ON DSCNT (BELOW 10000 FT) TRIED EXTENDING SPD BRAKES AND RECEIVED 'SPOILERS' EICAS AND CORRESPONDING ANNUNCIATOR LIGHT. FURTHER ON APCH; RECEIVED 'R YAW DAMPER' EICAS AND CORRESPONDING ANNUNCIATOR LIGHT. FELT NO DEGRADATION OF HANDLING OF ACFT. LANDED ACFT UNEVENTFULLY. ONLY PROC I FORGOT TO ACCOMPLISH; WAS NOTIFYING #1 FLT ATTENDANT OF EMER -- TUNNEL LOCKED ON FLYING ACFT.

Data retrieved from NASA's ASRS site as of May 2009 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.