Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical; Aircraft Equipment Problem Less Severe
Flight Crew Returned To Departure Airport; Flight Crew Landed As Precaution; General Declared Emergency; General Maintenance Action
Aircraft
During the climb; just about passing FL200; we received an ICAS warning of BLEED 2 FAIL. Normally; this would be a non-critical event; but in this case; our BLEED 1 system was already deferred; thus leaving us with NO bleed pressurization. I immediately stopped the climb and alerted ATC we needed a lower altitude immediately; while my first officer ran the QRH procedure. We were cleared to 10;000 and proceeded to initiate an immediate descent. We also asked for a turn back; and that was granted. We completed our descent in approximately three minutes. The QRH Procedure was successfully accomplished during the descent and we were able to restore pressurization in about a minute. The cabin altitude never exceeded 5000 feet and the emergency ram air system worked as advertised. As we had no idea what had caused the Bleed 2 system to shut down; we elected to return instead of trying to continue to destination with a possibly faulty pressurization system (Bleed 1 system was already deactivated by MEL; so we had no real backup system should it have failed again...). We were over 4000 pounds over our maximum landing weight; so after a ACARS discussion with dispatch and the fact there was no immediate need to land; we elected to hold and burn off the fuel to avoid the complications of an overweight landing. We descended to 8000 feet (going lower would have put us in constant light to moderate chop so we elected for some passenger comfort...); went to a high-drag configuration (gear-down; speed brakes out) and burned the fuel down to our maximum landing weight in about 20-25 minutes. We then proceeded to land without further incident. Contract maintenance met us at the gate and with maintenance control's help; troubleshot the system. It was determined this was only a transitory problem; so the logbook signed off and we left again 1:42 after we landed. No further incidents occurred en-route and we arrived approximately three hours late. The BLEED 1 system had been deferred after three write-ups for the same condition - BLEED 1 failures on the ground and in-flight - over the preceding several days. I realize that it is perfectly legitimate to defer items; but we need greater emphasis on getting critical items like bleed failures fixed quicker. Had a bleed failure like this occurred with both systems operating; we could have continued on and it would have been a non-event.
EMB-170 Captain reports being dispatched with the Number 1 bleed system deferred then having the Number 2 system fail passing FL200. An immediate descent is requested and the flight returns to the departure airport after burning down to landing weight.