B757 Undifferentiated or Other Model
Flight Crew Last 90 Days 172; Flight Crew Total 7058; Flight Crew Type 1513
Aircraft Equipment Problem Critical
Air Traffic Control Issued New Clearance; Flight Crew Returned To Departure Airport; General Declared Emergency
Aircraft
We just leveled off at FL380 in route; when an aural warning went off and an ECIAS message was on the ECIAS screen; 'CABIN ALTITUDE' Master warning. The Captain and I completed our memory items; O2 masks - Don and established communication. We evaluated the cabin pressure gauge and saw that the cabin was at 11;000 FT and climbing. We talked to ATC and requested lower. I started the descent. Next we evaluated where to go. With the destination weather 2 miles visibility and snow and having a MELed thrust reverser and being 20 minutes from the departure airport; we decided to go there. The Captain informed ATC of our return and declared an emergency. He also ran the checklists; talked to the flight attendants and passengers; and contacted operations. I continued descending the aircraft to a safe altitude in case we had a rapid decompression. The cabin never got above 14;000 FT and the passenger O2 masks never dropped. I do believe the highest the cabin got was 12;000 FT. Getting down to 11;000 FT we removed our masks. ATC handled our flight wonderfully and had us go direct to the outer marker and from that point forward the flight was routine and standard. I shot the visual approach and landed safely.
Lost cabin pressurization in cruise at FL380. Commenced descent and return to departure airport. Landed uneventfully.
B757 flight crew experiences a loss of cabin pressurization at FL380 and initiates an emergency descent and return to departure airport.