Date: 202011
Local time of day: 0601-1200
Location: ZZZ.ARTCC, US
Flight conditions: VMC
Light: Daylight
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Taxi
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class A ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Pressurization Outflow Valve
Component problem: Failed
Reporter organization: Air Taxi
Reporter function: Pilot Flying; First Officer
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine
Second reporter function: Captain; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Critical; Flight Deck / Cabin / Aircraft Event Other / Unknown
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Requested ATC Assistance / Clarification; Flight Crew Returned To Departure Airport; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Our preflight; deice; and taxi all went normal. We took Runway XX as cleared and took off. We made our initial climb and made our left turn towards ZZZZZ as directed by ATC. Sometime after that while in the climb we received an OVBD COOL caution message and INBD COOL FAIL status message. We ran the QRH and it advised to simply monitor pressure. All indications were in the green so we continued to climb. I noticed and brought cabin alt. to the Captain's attention when it was around 5;200 [ft.] and the cabin rate showing an increase. I were at about FL180 at that point. When the cabin got to around 6;000 [ft.] I brought it to his attention again. All indications were green at this time but the cabin alt. was slowly continuing to increase. When the cabin alt. turned yellow we immediately called ATC for lower and to return to ZZZ. They gave us 13;000 [ft.] and direct to ZZZ and we began our decent and turn back. We descended around 2;500 ft. per minute initially but then I increased it to 3;500 ft. per minute. We received a cabin alt. warning message while in the descent and we promptly put on masks [received priority handling] and ran the QRC then QRH. The cabin pressure started decreasing in the decent. I was still flying and talking to ATC. Captain was running the QRH; talked to the passengers dispatch and the flight attendant. The pressure stabilized around 13;000 [ft.] while in the descent but because of the terrain and altitude we had to level off at 13;000 [ft.] and not knowing when ATC could get us lower the Captain made [an] announcement to the pax (passengers) that masks were going to be dropped and then we dropped the passenger oxygen masks as directed by the QRC. At some point ATC asked if we wanted to divert to another airport and we declined due to the increased workload that would have presented to figure out new airport Information. We I ran for new landing numbers to make sure we wouldn't land over weight and we plugged in landing numbers from our speed cards. We used weather from when we took off from ZZZ and we ran the descent check when able. We knew winds favored Runway XX so we asked for the RNAV Runway XX received vectors and then landed. We then taxied to the gate and began calling the company to inform them we were ok and what happened. The cause of the event was the OVBD COOL and INBD COOL FAIL status message. We could have asked for lower or to divert sooner but we saw a slowing increase rate in cabin pressure and thought that it may have been a plane that kept higher cabin pressure. We monitored the pressure the whole climb out while everything was showing green indications and acted as soon as green indications went away.


Second narrative: After takeoff in the initial climb we received an OVBD COOL caution message and an INBD COOL FAIL status message and I ran the QRH for the OVBD COOL message and the QRH stated that if cabin pressure was normal that 'no further action required.' All indications at that time and continuing into the climb appeared normal. At approximately 18;000 feet I took a photo with my phone of ED 1 & 2 so I could remember what to write up when we got to ZZZ1. Indications at that time were normal showing a 100FPM rate up with a cabin altitude of 5;500 feet all indications were green. The First Officer and I were observant of the pressurization system as we discussed the training I had received in the hypobaric chamber. As we continued our climb at approximately 27;000 feet my First Officer pointed out that the cabin altitude readings felt a little high to him and this prompted me to open and begin reading the section on pressurization in PRM. At this time the cabin rate and cabin altitude began to increase at a quick pace and it became obvious that something was incorrect. I notified ATC that we were having a pressurization issue and that we needed to level off then begin a decent to 10;000 feet or the lowest he could give me with regards to the mountainous terrain in the area and that we would like a turn back. ATC gave us a decent clearance to 13;000 [ft.] and a left turn direct ZZZ. I entered ZZZ in the FMS and confirmed that 13;000 feet hand been entered into the altitude preselect. I had the First Officer continue flying and I started the CABIN ALT caution QRH after beginning the decent we got a CABIN ALT warning I then [received priority handling] with ATC and I began the QRC and QRH after donning my O2 mask and ensuring that the FO (First Officer) had donned his as well. I called the flight attendant and informed her that we were having a pressurization emergency that we were returning to ZZZ; that the O2 masks might drop and that we would be on the ground in approximately 18 minutes. I was hesitant to drop the masks if it was not 100% necessary so I again called the FA to [assess] the cabin and she didn't want to make the call so with the cabin altitude at approximately 13;000 [ft.] and no estimate of when we would be able to descend further I made a passenger announcement that we had had a problem with our pressurization system and that the oxygen mask above their heads would be dropping down momentarily I then selected the PASS OXYGEN switch light as directed by the QRC. I continued to run the QRH and communicate with ATC the workload was extremely high. After [descending] to a safe altitude I removed my mask and made a passenger announcement that it was now safe for them to remove their mask. We then attempted to get landing data for ZZZ but the FMS did not send back good data so I inputted the speeds manually off the 43;000 lbs. card. We ran the decent check and prepared the aircraft for landing. We landed in ZZZ without incident a smooth underweight touchdown well below 100FPM. We taxied to the terminal and I shut down the engines because we had received an ACARS message that ZZZ Operations had gone to lunch and there would be no one there to accept us. After a short while ZZZ ground staff arrived and I started up #2 and taxied to the gate. We were met by the fire crew and I answered his questions we then deplaned. All passengers appeared to be ok a few appeared slightly shook up from the experience. Failed OVBD COOL valve.


Synopsis: CRJ-200 Flight Crew reported overboard valve failure resulted in pressurization failure.