Date: 201807
Local time of day: 1201-1800
Location: ZZZ.ARTCC, US
Flight conditions: Marginal
Light: Daylight
Aircraft: EMB ERJ 145 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
ATC / advisory: Center ZZZ
Aircraft component: Pressurization Control System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Second reporter function: Pilot Not Flying; First Officer
Anomaly: Aircraft Equipment Problem Less Severe
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Overcame Equipment Problem; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action
Contributing factors: Aircraft; MEL
Primary problem: Aircraft

Narrative: While flying in cruise flight; I felt the pressurization in my ear drums change and that prompted me to look at the cabin altitude on the EICAS display. I noticed that the cabin pressure was climbing rapidly. I immediately [advised ATC] and executed the emergency descent with the intent to level off at 10;000 feet. While we were approaching FL180 the First Officer noticed and verbalized that the pressurization was normalizing and trending towards a stable pressurization in line with the QRH pressurization table. At that point I shallowed the descent to level off at FL180 to eventually receive a clearance from ATC to 17000 feet. While working through the pressurization QRH ERRATIC RATE FLUCTUATIONS MAY BE PRESENTED in the QRH (and also referencing LOSS OF PRESSURIZATION INDICATION table in the QRH) and discussing our options with crew and notifying dispatch; our fuel was sufficient to continue to ZZZ. We landed at ZZZ (our original destination) and had emergency response personnel roll the trucks due to a BLD 2 OVERTEMP earlier in the flight. Since we had a BLEED 2 over temperature issue earlier in the flight along with an MEL'd PACK 1 overload; I erred on the side of caution for landing to be sure we had no unknown heat related issues that would jeopardize the condition of the aircraft. We kept the Flight Attendant in the loop and after the flight; she mentioned that passengers were basically unaware of the condition of the challenges that we faced during the flight. In my view; the flight attendants did a good job of keeping passengers calm and informed.While executing the emergency descent procedure; I realized that we were able to achieve a stabilizing cabin pressure altitude during the procedure. I made the decision at that point to return the aircraft to a normal shallow descent configuration because in my view; we were in no immediate danger of further depressurization. I realized at that point that we can bring everything back into a normal state after assessing fuel loads and discussion with the First Officer and input from dispatch.I just had recurrent training and the emergency descent procedures were practiced and the continued training received from the training center and challenging scenarios played a vital role in completing the remainder of this flight. Continued vigilance and adherence to the [flight manuals] and scenario based challenges from the training center.


Second narrative: Cabin altitude started climbing rapidly while at FL240. 6;500 feet was the highest cabin altitude reached; cabin oxygen masks did not deploy. CA (Captain) recognized the issue when his ears started popping. CA immediately [advised ATC] and executed an emergency descent to FL180. FO (First Officer) recited emergency descent memory items. Immediately upon descent; cabin altitude started decreasing. Once at FL180; ATC assigned us FL170 for traffic. During the emergency; we referenced the 'Cabin Rate Abnormal Fluctuations' and 'Loss of Pressurization Indication' checklists in the QRH. It was not necessary to push the manual pressurization button since the cabin altitude started to decrease. Based on referencing the 'AIRPLANE ALTITUDE/CABIN ALTITUDE CONVERSION TABLE' within the 'Loss of Pressurization Indication' checklist we determined our cabin altitude for FL170 was normal. We then apprised Dispatch of our situation and agreed our flight should continue to ZZZ. The remainder of our flight was flown at FL170. We landed with no issues. Advised maintenance at ZZZ and CA wrote the issue up in the [log book].


Synopsis: ERJ-145 flight crew reported the cabin altitude started climbing rapidly while at cruise altitude.