EMB-175 flight crew reported a depressurization during departure climb.
Synopsis
EMB-175 flight crew reported a depressurization during departure climb.
Narrative
After a normal departure from ZZZ on Day 0 on a flight from ZZZ-to ZZZ1 on the ZZZX SID; we experienced a decompression event that necessitated an emergency descent; request of priority handling to ATC; and return to ZZZ for a precautionary landing.After executing a normal departure and climbout on the ZZZX departure; while passing approximately 16;000 ft. MSL; both the First Officer (FO) and I; as Captain/pilot flying; noticed the Cabin Pressure Indicator Gage on the EICAS screen turn to yellow indications; with cabin pressure indicating around 8;700'. At the time; no other indications were present and the aircraft was climbing normally; so I took a few seconds to monitor the gauges and seek more information. However; after only a few seconds; we registered that the cabin pressure continued to climb rapidly and soon turned to red indication with the corresponding CABIN ALTITUDE HI" EICAS message displayed. I called for the QRC procedure and for us to don our oxygen masks. This process took a few seconds and I prioritized donning masks over leveling or descending the aircraft as both the FO and I were feeling tingling and lightheadedness. The aircraft was passing roughly 21;000' MSL by the time we were on oxygen and able to call for the Emergency Descent QRC. I remember seeing cabin pressure reach approximately 13;000' and first wanted to level the aircraft using the ALT button - because I inadvertently knocked my glasses off my head during the donning process and my mask immediately started to fog up; it took both the FO and myself approximately 5 seconds more to find the ALT button to select.I then spun the altitude selector to 10;000'; turned to Green FLCH mode; and extended the speed brakes as I called for the Emergency Descent QRC. The FO recited the procedures as I verified them and called ATC to request priority handling. We briefly talked about calling the flight attendants to see how they were affected and see if the masks had deployed; the FO called them and confirmed with them that they had heard his announcement; understood we were in an emergency descent; but that the masks in the cabin had not deployed.The descent took approximately three minutes to accomplish; including ATC inquiries to what our aircraft state was and authorization to turn directly to ZZZ for a landing. Reaching 10;000ft; we noted cabin pressure returned to a green indication; although it was higher than normal for that altitude - the gauge read approximately 8000 cabin pressure at 10;000'MSL. The FO and I quickly briefed our plan and intentions to return to ZZZ for landing. Being close to the airfield; we prioritized accomplishing landing tasks for a safe landing and in doing so; I did not attempt to conduct the QRH procedure. As the FO was programming the FMS for our return; I made a cabin announcement to the passengers; stating that our pressurization system was unable to maintain a safe environment at higher altitudes and that we had executed a rapid descent to maintain a safe altitude for the plane and would be returning to ZZZ for a precautionary landing. I was also able to send a brief ACARS message to dispatch confirming our return-to-base and another brief message to Maintenance that the ECS system had depressurized. As well; we updated ATC on our situation; informing them that we did need to return; but that the cabin pressure had returned to a stable and safe range and that we did not need emergency services to meet our aircraft upon landing. There was little time for any other tasks; and we prioritized making a safe landing.After landing; we coordinated for a return gate and taxied without incident to a gate; where all passengers were deplaned. During deplaning; the FO and flight attendants focused on ensuring it was an orderly and efficient process - they did not note any unusually flustered passenger behavior; digital usage; or other notable action. I coordinated with maintenance and wrote a maintenance action for the event. After all passengers were deplaned; we debriefed as a crew. The flight attendants reported that during the event; they also felt lightheaded. We reviewed our actions during the event and made an honest assessment of our mental and physical states with all of us concluding that while the event had been stressful; we were all safe and willing to fly. I coordinated with the Maintenance Operations Manager; Dispatch; and the regional controller for reporting requirements and a new airplane. We switched planes; executed the remained of our flight schedule for the day; ended with a thorough debrief; and all completed our required reports.Cause: This was a safety/depressurization event. It was an aircraft system malfunction of the ECS system. At this time; I do not know what maintenance actions were completed after our return or any more specific information regarding the malfunction.Suggestions: This was a safety event that was not pilot-induced; I do not have any suggestions to avoiding this event in the future. However; there were plenty of learning lessons that I will take away; including:Things I think went well:(1) We recognized the indications and took timely and appropriate initial actions; including the Cabin Alt Hi and Emergency Descent QRCs. The FO was clear and concise in his announcements and requesting priority handling with ATC.(2) We were able to recognize the condition and began the descent before the cabin pressure reached 14;500 or deployed the cabin masks; avoiding undue passenger panic and keeping the pressure from rising too much.(3) The FO did an excellent job at both ensuring the FAs were initially informed and seeking more initial information; and also requesting priority handling with ATC. He also did a great job using the QRC in accordance with our training and completing tasks for our return to ZZZ.Things that could have gone better:(1) Even though the event unfolded quickly; I should have called for the QRH as part of our return to ZZZ.(2) Even though I think we made all our appropriate calls; I could have been clearer and more precise in my communication; both in making the passenger announcement and setting better expectations with our flight attendants for the plan for our return; taxi; and deplaning.(3) I could have been more clear and systematic in working through the completion of the QRCs."
Second reporter narrative
After a normal departure off of Runway XX at ZZZ while on initial climb to ZZZ1 on the ZZZX SID; we experienced a depressurization event that necessitated an emergency descent; priority handling with ATC and a return to ZZZ for a precautionary landing.While climbing through 16;000 ft; both the Captain and I noticed a Cabin Pressure Indicator on the EICAS to be yellow and around 8;500 ft. At this time there were no indications/messages present and the aircraft was climbing normally so we both continued to monitor the gauge. A few seconds later the gauge indicated approximately 13;000ft and the plane notified us of a CABIN ALT HI red warning message. We immediately donned our oxygen masks. It should be noted we both felt tingliness and lightheadedness during the event as well as our ears popping. The Captain immediately level off and executed and Emergency Descent while calling for the Emergency Descent QRC. The aircraft climbed to approximately 21;000ft at the time the descent was initiated.While the captain initiated the descent; I [requested priority handling] with at who instructed us to turn 20 degrees to the left. I then read the QRC aloud and complied with the checklist. I stated FLIGHT ATTENDANTS EMERGENCY DESCENT on the PA system. I then utilized the emergency button on the interphone to obtain a status from the cabin. They stated the passengers were calm; everyone was conscious and the oxygen masks did not deploy.The descent took approximately three minutes to reach a safe altitude of 10;000 ft. ATC cleared us direct to ZZZ for landing on any runway. The Captain and I briefed a plan for our arrival into ZZZ and precautionary landing. I programmed the RNAV Z XYR into the FMS and began coordinating with Approach Control. ATC inquired several times if Emergency Services were required on the ground - as the cabin was stabilized and passengers and crew were safe we did not require assistance on the ground.The plane arrived safely on Runway XYR at approximately XA:16. No injuries were reported by crew or passengers.Cause: This was a safety/depressurization event relating from an aircraft system malfunction of the ECS system. I have no further information as to the findings by maintenance personnel.Suggestions: This was an equipment malfunction relating in a safety/depressurization event that was not pilot-induced.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.