Narrative:

We were dispatched with bleed 1 deferred. At 23;000 ft on climb we received a caution bleed 2 fail. Stopped climb at 23;000 to run bleed 2 fail checklist. [We were] unable to reset. Noticed cabin altitude was beginning to climb ATC could not issue an immediate descent to 10;000 therefore we declared an emergency to begin descent immediately. [We] continued to run APU in flight start checklist. Upon passing through 15;000 the APU bleed came online to begin providing pressurization again. Cabin altitude message was displayed for 30 seconds before cabin altitude message disappeared as a result of cabin pressurization being regained. Contacted dispatch agreed to reroute to a nearby airport. As a result of having an alternate on our paperwork we were carrying extra fuel. Now we had a planned overweight landing; as a result we dropped altitude to lowest level for radar coverage and flew to our alternate at altitude of 4;000-10;000 ft to increase fuel burn. [We] landed at our alternate with 74;900 pounds.perhaps not add alternates unless absolutely needed. Extra 2;000 pounds of fuel added to an already busy flight deck. Also company decided to defer bleed 2 and fly to destination at 15;000 ft with the APU running. Obviously many passenger would not get back on the plane as they just went through a diversion and rapid descent and flight at 4;000 ft for 1 hour plus. I tried to talk to individual passengers and assure them I would not fly a plane I thought was not capable of getting to destination. Many passengers were still uncomfortable and decided not to re-board the flight. Perhaps next time people go through something like that we should ensure they continue on an aircraft that doesn't get dispatched with the same problem we diverted for.

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Original NASA ASRS Text

Title: EMB170 Captain reports being dispatched with Bleed #1 deferred and having Bleed #2 fail at FL230. An emergency descent ensues with APU bleed restoring pressurization at 15;000 FT. Crew diverts for maintenance where Bleed #2 is deferred and the flight continues to destination using APU bleed air for pressurization.

Narrative: We were dispatched with bleed 1 deferred. At 23;000 FT on climb we received a caution bleed 2 fail. Stopped climb at 23;000 to run Bleed 2 Fail checklist. [We were] unable to reset. Noticed cabin altitude was beginning to climb ATC could not issue an immediate descent to 10;000 therefore we declared an emergency to begin descent immediately. [We] continued to run APU in flight start checklist. Upon passing through 15;000 the APU bleed came online to begin providing pressurization again. Cabin altitude message was displayed for 30 seconds before cabin altitude message disappeared as a result of cabin pressurization being regained. Contacted Dispatch agreed to reroute to a nearby airport. As a result of having an alternate on our paperwork we were carrying extra fuel. Now we had a planned overweight landing; as a result we dropped altitude to lowest level for radar coverage and flew to our alternate at altitude of 4;000-10;000 FT to increase fuel burn. [We] landed at our alternate with 74;900 LBS.Perhaps not add alternates unless absolutely needed. Extra 2;000 LBS of fuel added to an already busy flight deck. Also company decided to defer bleed 2 and fly to destination at 15;000 FT with the APU running. Obviously many passenger would not get back on the plane as they just went through a diversion and rapid descent and flight at 4;000 FT for 1 hour plus. I tried to talk to individual passengers and assure them I would not fly a plane I thought was not capable of getting to destination. Many passengers were still uncomfortable and decided not to re-board the flight. Perhaps next time people go through something like that we should ensure they continue on an aircraft that doesn't get dispatched with the same problem we diverted for.

Data retrieved from NASA's ASRS site as of April 2012 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.