Narrative:

On climb out we got a left engine bleed air off light on the overhead panel. There were no other abnormal indications. We referred to the checklist; recycled the switch; adjusted power; etc. No luck; the light stayed on. We sent a code to maintenance control via ACARS. The captain and I discussed the situation to include aircraft pressurization; which was O.K. (Still climbing to cruise altitude of FL380); and whether the current bleed air off light was a normal condition as per the current deferral. There was some confusion at this point because the deferral was not totally clear and the left pack was operating with approximately 10 psi in the left duct. The captain was discussing the situation with maintenance control via ACARS while the aircraft leveled off at FL380. The aircraft started to get warm throughout; and in an effort to cool it off the right pack ended up in the standby/cold position; this was the only thing that was effective. In cruise at FL380 we got a master caution/warning for cabin altitude with the associated EICAS. We donned our oxygen masks; initiated an emergency descent with ATC; and ran the cabin altitude QRH. While accomplishing the items in the QRH; I noticed automatic inoperative illuminated on the cabin altitude control panel. I selected the manual position and closed the outflow valve. We ran the cabin automatic inoperative QRH and continued our descent to 10;000 ft. Somewhere in the descent we managed to get control of the cabin altitude. While the cabin altitude did exceed 10;000 ft; it did not exceed 14;000 ft and the cabin oxygen masks did not deploy. After conferring with the captain; the flight attendants; and dispatch we elected to proceed to destination at 10;000 ft.

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Original NASA ASRS Text

Title: B757 First Officer reports being dispatched with an unspecified bleed air MEL deferral which may have been a factor in the illumination of a LEFT ENGINE BLEED AIR OFF light during climb to FL380. With the right pack set to standby cold to maintain a reasonable cabin temperature the cabin altitude warning sounds and an emergency descent is initiated. Control of the outflow valve is regained manually and the flight continues to destination at 10;000 FT.

Narrative: On climb out we got a LEFT ENGINE BLEED AIR OFF light on the overhead panel. There were no other abnormal indications. We referred to the checklist; recycled the switch; adjusted power; etc. No luck; the light stayed on. We sent a code to Maintenance Control via ACARS. The Captain and I discussed the situation to include aircraft pressurization; which was O.K. (still climbing to cruise altitude of FL380); and whether the current Bleed Air Off light was a normal condition as per the current deferral. There was some confusion at this point because the deferral was not totally clear and the left pack was operating with approximately 10 psi in the left duct. The Captain was discussing the situation with Maintenance Control via ACARS while the aircraft leveled off at FL380. The aircraft started to get warm throughout; and in an effort to cool it off the right pack ended up in the standby/cold position; this was the only thing that was effective. In cruise at FL380 we got a Master Caution/Warning for cabin Altitude with the associated EICAS. We donned our oxygen masks; initiated an emergency descent with ATC; and ran the Cabin Altitude QRH. While accomplishing the items in the QRH; I noticed AUTO INOP illuminated on the Cabin Altitude control panel. I selected the Manual position and closed the outflow valve. We ran the CABIN AUTO INOP QRH and continued our descent to 10;000 FT. Somewhere in the descent we managed to get control of the cabin altitude. While the cabin altitude did exceed 10;000 FT; it did not exceed 14;000 FT and the cabin oxygen masks did not deploy. After conferring with the Captain; the flight attendants; and Dispatch we elected to proceed to destination at 10;000 FT.

Data retrieved from NASA's ASRS site as of July 2013 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.