Narrative:

Aircraft landed at delhi with a hydraulic overheat system #3 logbook entry. System components were inspected, an idle engine run conducted, and the discrepancy cleared by maintenance personnel. On subsequent flight to stansted, at FL280, the EICAS message hydraulic overheat system #3 was displayed. The QRH checklist was completed. The message remained displayed, so both hydraulic pumps were left off. Reduced stabilizer trim rate and reduced spoiler capability were briefed from the QRH. Descent and approach to stansted were briefed by the PF, the first officer. The autoplt performed several intermediate leveloffs normally. While slowing the aircraft on radar vectors to downwind to runway 5, descent clearance to 6000 ft on qnh 1001 was received and initiated on autoplt in flight level change. FMA progress was noted normal, speed and altitude, upon approaching 6000 ft, when our attention was diverted to a TA. We sighted, below to our left, a B737 also on radar vectors to stansted, with both aircraft above a solid undercast. I then noticed the pfd white altitude box turn amber, noted approximately 5700 ft descending, and called for immediate climb. At the same time, the first officer was disconnecting the autoplt to climb and our essex controller called with climb instructions. In manual flight, heavy aircraft nose down trim was noted, due to the reduced stabilizer trim rate, which the autoplt was apparently not able to counter. The aircraft was trimmed and autoplt re-engaged until on ILS final. A normal landing was conducted.

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Original NASA ASRS Text

Title: B747-400 FLC CLBED IN RESPONSE TO TCASII RA AND APCH CTLR CLB INSTRUCTIONS. IN ADDITION, THE ACFT'S HYD SYS WAS MALFUNCTIONING AGAIN AFTER BEING CLRED BY MAINT FOR PREVIOUS WRITE-UPS.

Narrative: ACFT LANDED AT DELHI WITH A HYD OVERHEAT SYS #3 LOGBOOK ENTRY. SYS COMPONENTS WERE INSPECTED, AN IDLE ENG RUN CONDUCTED, AND THE DISCREPANCY CLRED BY MAINT PERSONNEL. ON SUBSEQUENT FLT TO STANSTED, AT FL280, THE EICAS MESSAGE HYD OVERHEAT SYS #3 WAS DISPLAYED. THE QRH CHKLIST WAS COMPLETED. THE MESSAGE REMAINED DISPLAYED, SO BOTH HYD PUMPS WERE LEFT OFF. REDUCED STABILIZER TRIM RATE AND REDUCED SPOILER CAPABILITY WERE BRIEFED FROM THE QRH. DSCNT AND APCH TO STANSTED WERE BRIEFED BY THE PF, THE FO. THE AUTOPLT PERFORMED SEVERAL INTERMEDIATE LEVELOFFS NORMALLY. WHILE SLOWING THE ACFT ON RADAR VECTORS TO DOWNWIND TO RWY 5, DSCNT CLRNC TO 6000 FT ON QNH 1001 WAS RECEIVED AND INITIATED ON AUTOPLT IN FLT LEVEL CHANGE. FMA PROGRESS WAS NOTED NORMAL, SPD AND ALT, UPON APCHING 6000 FT, WHEN OUR ATTN WAS DIVERTED TO A TA. WE SIGHTED, BELOW TO OUR L, A B737 ALSO ON RADAR VECTORS TO STANSTED, WITH BOTH ACFT ABOVE A SOLID UNDERCAST. I THEN NOTICED THE PFD WHITE ALT BOX TURN AMBER, NOTED APPROX 5700 FT DSNDING, AND CALLED FOR IMMEDIATE CLB. AT THE SAME TIME, THE FO WAS DISCONNECTING THE AUTOPLT TO CLB AND OUR ESSEX CTLR CALLED WITH CLB INSTRUCTIONS. IN MANUAL FLT, HVY ACFT NOSE DOWN TRIM WAS NOTED, DUE TO THE REDUCED STABILIZER TRIM RATE, WHICH THE AUTOPLT WAS APPARENTLY NOT ABLE TO COUNTER. THE ACFT WAS TRIMMED AND AUTOPLT RE-ENGAGED UNTIL ON ILS FINAL. A NORMAL LNDG WAS CONDUCTED.

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.