EMB ERJ 170/175 ER/LR
Flight Crew Air Transport Pilot (ATP)
Communication Breakdown
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Aircraft; Procedure
Yesterday morning; I read in the [company] daily email updates; that Aircraft X had the APU bleed valve put back on deferral. We had this same problem [previously]. However; we also had a CAS message displayed on both PFDs. Maintenance did not know how to address the CAS Message; and wanted to defer the APU Bleed and dispatch the aircraft. When toggling through the CAS selection prompts on the MCDU; we were able to determine that the CAS MSG was due to the #2 EICAS displaying the following messages: A-I WING FAIL; BLEED 2 FAIL; and BLEED 1 FAIL. It should be noted that the APU bleed could be cycled ON-OFF and it responded; accordingly. When we refused to take the aircraft with the CAS MSG; Maintenance came out to the aircraft and was able to reset the power; and all faults cleared.A review of the aircraft logbook showed that the APU bleed had been previously written up several times. The APU bleed is not the problem. The #2 EICAS is seeing an erroneous bleed leak; and this is causing the X-ing out the bleed valve (if were it an actual bleed leak; the APU bleed valve would not be able to open up when commanded to do so).After finding that the APU Bleed was unnecessarily put back on deferral; I tried to reach out to Maintenance-Control; but they were too busy to take my input.My concern is this: we have an aircraft that was improperly deferred and is flying around with an illegal deferral. Almost as important; we have a much-needed system which is on deferral; yet the system is completely operative.Put out some type of advisory and/or memo to all Maintenance personnel; on how to accurately troubleshoot/diagnose an EICAS miscompare.
An EMB-175 First Officer reported that the APU bleed was unnecessarily deferred when other pneumatic system faults were displayed on EICAS.