B757-200
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport
Aircraft
Had just leveled off about 200 NM east of ZZZ; EICAS L HYD Quan amber message appeared. Status page showed .46 quantity in left system and RF displayed. RSVR light on overhead panel was illuminated. We accomplished B757 QRH for Hydraulic Quantity for the left system. Nothing to do there; we began reviewing QRH for Hydraulic System Pressure (L ONLY) in the event that this would occur. Aircraft was dispatched under an MEL for the center electric right press indication. This probably had nothing to do with our problem; although we did think that at this time our problem was only an indicator problem; as all other parameters; including left system hydraulic pressure were normal. About 10 minutes later we received a call from the Number 2 Flight Attendant that numerous passengers were reporting fluid all over the right wing surface. This confirmed to us that we did indeed have a hydraulic leak. We declared an emergency with Center and turned around to ZZZ. We were about 250 miles west of ZZZ at this time with about 33;000 LBS of fuel. When we were headed back to ZZZ; Dispatch was informed via ACARS. Our previous review of QRH for system loss; confirmed that we would possibly be using alternate gear and flap extension if the normal and or PTU were ineffective. About 150 miles from ZZZ; the quantity had fallen to .21 system pressure was still good. I asked for a descent to FL180 in order to attempt to configure the aircraft for a normal landing before we lost all quantity and was down to depending on only the alternate methods. We were cleared to 16;000 FT. Slowed to about 235 KIAS and lowered the landing gear. It went down normally. Quantity and pressure remained as before. Slowed to 220 KIAS and lowered flaps 1. Normal operation; continued to slow as appropriate for flap speeds and attained flaps 20. We continued until about 100 miles from ZZZ and the quantity began falling; accompanied by an intermittent Hydraulic Engine Pump indication. While the light was out; we configured to flaps 25 for a normal landing. After this; the engine pump light came on steady and then the sys press caution light illuminated. Accomplished QRH for the pump and for the pressure; only item remaining was to turn off l electric hydraulic pump. As stated in the checklist; some spoilers would not work and roll rate might be reduced. We were flying with center autopilot engaged; and when the system failed; it was unable to control the roll axis. Autopilot was disconnected and it required 5 units left rudder trim and left aileron trim to maintain level flight. Nice to discover while still 25 minutes from landing. Flight Attendant coordination was accomplished and the passengers were informed and reassured that a normal landing would occur. Hand flew an ILS to ZZZ [and] landed as previously configured with flaps 25. Weight had been conveniently burned down to about 196;000 LBS. Rolled to the end; used differential braking to clear and had Maintenance meet us to pin the gear and tow in. Manual spoiler was planned and accomplished. Left reverser was inoperative. Turns out the number 2 spoiler actuator on the right wing; according to a preliminary report from maintenance after parking; had sprung a leak. Open for comments on decision to configure early. As far as my research indicates it did nothing to compound the problem. Fuel needed to be burned down anyway. Why wait to see if the backup methods would work? Always do in the SIM; but who knows when they were tested on the real thing?
Approximately 45 minutes after takeoff and soon after reaching our cruising altitude of FL380; we got an L HYD QTY EICAS message. The reservoir level was less than full; therefore we observed the RF; however the system pressure was normal. We referenced the QRH for the low quantity but all it says is confirming that the quantity is low leading us to conclude it must be an indication error. We pressed on when we got a call from the back that a passenger could see fluid leaking from the top of the right wing; simultaneously the left engine hydraulic pump pressure light began to flicker followed by coming on steady; we followed the QRH procedure; but our attention now was on an impending Left Hydraulic System failure. We declared an emergency and given our relative position; it was wiser and closer to return to ZZZ. We descended to 16;000 FT and slowed the airplane to an airspeed so that we can lower the flaps and the landing gear without exceeding a limitation. Soon after we got the LEFT SYSTEM light and corresponding EICAS message and our indications confirmed that both quantity and pressure very severely low. We landed uneventfully; but since we didn't have nose wheel steering; we exited the runway at the very end; parked the jet and waited for Maintenance to tow us to the gate. On arrival; a mechanic came to the cockpit and informed us that the culprit was a leaking spoiler panel actuator.
B757 flight crew experiences loss of hydraulic fluid from the left hydraulic system at FL380. The crew elects to return to the departure airport and extend the gear and flaps before the fluid is depleted. An overweight landing ensues.