Troubleshooting
Aircraft Equipment Problem Critical
Flight Crew Returned To Departure Airport; General Flight Cancelled / Delayed; General Maintenance Action
Aircraft
On initial takeoff and climb; I noticed that airflow in the cockpit was surging. I remembered that in January 2015; there was a write-up in the Aircraft Maintenance Logbook (AML) regarding a problem with both engine bleeds. When I looked in the Environmental Control System (ECS) page; I noticed that bleed 1 and 2 output was erratic and rapidly surging from 0 to 78 psi. I contacted local ZZZ Maintenance over the radio. I sent a message to dispatcher and copied Maintenance Control. The rate that the cabin was being pressurized was erratic. I made the decision to return to ZZZ due to safety concerns that we could lose pressurization at our cruising altitude (FL380). I sent a message via ACARS to the dispatcher [about] the diversion. No emergency was declared. No overweight landing performed (landed at 93;000 lbs. which is 4;000 lbs below maximum landing weight). I made an entry on the AML upon gate arrival in ZZZ. Erratic pressure output of both engine bleed 1 and 2. Captain EMB190. Air turnback.
Reporter stated the ERJ-190 uses an EICAS alerting system. After he returned to their departure airport; mechanics had asked him if he noticed the pneumatic cross-bleed valve was open during the erratic rapid surging? The thought by Maintenance was; if the Cross-bleed was open; then possibly the bleed valves on each engine were fighting each other; causing the surging. The only indication he had occurred during their takeoff roll when he noticed a Pack 1-2 EICAS message that happened very briefly and went away; no fault messages appeared. At the same time he did hear a surging noise that sounded like a window was open. As they were climbing he could feel pressure bumps as the surging increased. He decided to return to their departure airport. The ERJ-190 does not have a Fuel Dump System. Reporter stated the ERJ-190 aircraft uses a System Logic approach in the pneumatic system that opens and closes pneumatic valves automatically through an onboard Air Management System (AMS) computer that gives priority to the APU Bleed valve. Flight crews can switch to the opposite Pressure Controller; but do not have a 'Manual' control feature that allows pilots to manually adjust cabin pressure. Maintenance did perform a lengthy cabin pressurization check; suspecting the AMS computer; but ended up taking the aircraft out of service; the Corrective Action fix was unknown. He was given another aircraft and departed.
A Captain reports that during initial climb he noticed the airflow in the ERJ-190 cockpit was surging. Both engine bleeds were erratic and rapidly surging from 0 to 78 psi. Crew returned to departure airport due to concerns for losing cabin pressurization at cruising altitude of FL380.