Narrative:

30 minutes into cruise flight at FL400; EICAS message left bleed off. QRH consulted and complied with. Pressurization held cabin altitude; flight continued. Approximately 30 min later; EICAS message right bleed off. Immediately donned O2 mask; advised ATC of descent needed for pressurization problem and complied with QRH while descending to 10;000. Reset bleed valves and they responded and regained pressurization control. Cabin altitude stabilized. We leveled at 15;000. Everything then stabilized; pressurization; and left and right bleeds. At this point we were within 100 miles to STAR for destination airport. Elected to continue to destination airport. No further malfunctions concerning these systems occurred.

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Original NASA ASRS Text

Title: A Boeing 757 flight crew reported a failure of both engine bleed air valves resulting in a gradual loss of cabin pressurization. After troubleshooting the problem they were able to restore the engine bleed system to normal operation and regain cabin pressurization. They proceeded to the destination airport and landed uneventfully.

Narrative: 30 minutes into cruise flight at FL400; EICAS message L Bleed Off. QRH consulted and complied with. Pressurization held cabin altitude; flight continued. Approximately 30 min later; EICAS message R Bleed off. Immediately donned O2 mask; advised ATC of descent needed for pressurization problem and complied with QRH while descending to 10;000. Reset bleed valves and they responded and regained pressurization control. Cabin altitude stabilized. We leveled at 15;000. Everything then stabilized; pressurization; and L and R Bleeds. At this point we were within 100 miles to STAR for destination airport. Elected to continue to destination airport. No further malfunctions concerning these systems occurred.

Data retrieved from NASA's ASRS site 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.