EMB-XRJ flight crew reported a pressurization problem in cruise and possible hypoxic symptoms exhibited by the Captain.
Synopsis
EMB-XRJ flight crew reported a pressurization problem in cruise and possible hypoxic symptoms exhibited by the Captain.
Narrative
During flight from ZZZ to ZZZ1 we experienced pressurization issues during cruise that resulted in us [requesting priority handling] and exercising an emergency descent. Pressurization was normal during our climb; and when leveling off at 29000 ft. However; after I started working on landing data for ZZZ1 Captain noted that our cabin altitude indication on the EICAS had risen to 8400 ft. He asked me to request a lower altitude from ATC while we began running the Pressurization automatic system failure/Cabin depressurization/Cabin rate abnormal fluctuations QRH items. ATC told us to descend to 24000 ft. During our descent our cabin altitude indication continued to rise and when it reached 9000 ft Captain said that he was light headed and said to don our oxygen masks; and to [request priority handling] with ATC and request a descent to 10;000 ft. I complied with the Captains request and accomplished the O2 mask donning procedure QRC items; then spoke to ATC while he advised our Flight Attendant of the situation and possible diversion. We then completed the Emergency Descent QRC items. We informed Dispatch of the situation via ACARS; and began planning to divert to ZZZ2. However; we received a message from Dispatch advising us that our original destination was the same distance as ZZZ2; and that we had plenty of fuel to make it there as well so we continued to ZZZ1. After completing the QRH items; we were able to gain some control of our cabin pressure. However; I believe that had we not descended and [advised ATC]; our cabin altitude would have risen higher and resulted in the passenger oxygen masks dropping. After completing the QRH items and reaching 10;000 ft.; we communicated with our Flight Attendant and she advised that there were no injuries among passengers; and that the passenger oxygen masks had not dropped. We continued to ZZZ1 at 10;000 ft. and landed on Runway XX normally.
Second reporter narrative
Today on flight from ZZZ to (ZZZ1) on Aircraft X; we (CA (Captain); FO (First Officer) and Flight Attendant (FA) [request priority handling] in air for a pressurization issue. Below are the detailed sequence of events and action performed by our crew. As the Pilot Flying (PF) approximately 105 miles to ZZZ1 and 100 miles to ZZZ2 at 29;000 ft. we realized our cabin altitude pressure started to flash amber with an initial reading of a cabin climb rise of 8400 ft. At that point I had pointed to the FO [Pilot Monitoring (PM)] the EICAS Non-Annunciated message/discrepancy. During that time frame I started to feel and experience the symptoms of Hypoxic Hypoxia (Light Headed and small happiness laughter). As a prior/retired military pilot I am trained and certified in high altitude chamber operations. This certified training provided me with the training in knowing and experiencing the symptoms of Hypoxia and how they personally affect me. Utilizing CRM; I then directed the FO to Don his mask also per the QTC 'O2 MASK DONNING PROCEDURE' and to request from ATC for a lower altitude to allow us to diagnose the current issue and see if the indications would improve. The FO contacted ATC (Center) to request a lower altitude available within our dispatched release paperwork parameters (23000 to 29000 ft.); ATC granted us a FL240 (24;000 ft.). Upon reaching 24;000 ft. we noticed the Cabin Altitude go from 8400 ft. rapidly to 9000 ft. and continue to rise. Hypoxic symptoms started to increase. I then directed the FO to contact ATC and [advise priority handling] due to the loss of pressurization and to request a rapid descent to 10;000 ft. or MEA; which ever was higher. ATC granted an emergency descent to 10;000 ft. or MEA per the QRC-EMERGENCY DESCENT. We then initiated the Emergency Descent following the QRC memory items; and then leading into the QRH to XXX-XX-XXX (CABIN DEPRESSURIZATION and CABIN RATE ABNORMAL FLUCTUATIONS (per the QRC). I (CA); then directed the FO (PM) to continue to communicate with ATC. I plotted the approved alternate airport in my JEPPS and noticed that ZZZ2 was 5 miles closer than what ZZZ1 was. I also calculated our burn rate for 10;000 and we had enough fuel for both airports with a REM of 2.3 at touch down. At the same time we were sending the Dispatcher ACARS messages informing [Operations] of our problem; souls on board (SOB); Fuel on Board and requesting for fuel and divert airport calculations accordingly. We had analyzed and reviewed a desire to go to ZZZ2; but just as we were going to recommend it to [Operations]; Dispatch contacted us through ACARS and stated to continue to ZZZ1. Both the FO and I agreed so we then told ATC our intentions to continue to ZZZ1 and executed the requirements per our QRH. Dispatch wanted to conduct an ARINC call; but we were too busy executing; reading the QRH and executing our plan for Runway XX into ZZZ1. I free texted the Dispatcher and express that I will call upon landing. I then pressed the EMER CALL button for the FA; the FA answered and I told her that I have an NTSB and to calmly listen (Hard to talk with the Mask on). I told the FA the Nature of the emergency-- That we had to initiate a rapid descent and that there is currently indications of a rapid cabin pressure climb; for the type of emergency; I had expressed to her that we were performing actions per the QRC and then followed by some troubleshooting as directed by the QRH/ checklist. Additionally informed her that we are still going to ZZZ1 and that we should be descending to 10;000 ft. soon (time). I had expressed that no bracing was needed and additionally asked for her to put on her O2 mask in case the pressurization gets worst before we can reach to between 14000 to 10;000 ft. Additionally; requested for her to please brief the passengers that I had initiated an emergency descent for a pressurization problem and that all is ok and under control. Also specified to her that we will level off at 10;000ft. and run the QRH actions. Furthermore; I expressed to the FA that I will brief the passengers over the PA system soon after all is calm and we can complete all of the QRH items. Both the FO and I ran the QRH and performed the steps per the instructions. No more symptoms of Hypoxic Hypoxia were experienced. The Manual operation dumped the cabin and all was ok at 10;000 ft. It's to note that During the descent the Cabin climbed to 8700 ft. and as we slowly used the chart to control the cabin manually the pressurization equalized at above 400 with a differential of 4.0. We were given priority to ZZZ1 for Runway XX. We had informed ATC and ZZZ1 Tower that we would not need the emergency trucks upon landing. ATC also asked if the passenger masks deployed; we said 'NO'. We then executed the approach for the visual to Runway XX into ZZZ1 and no further pressurization dilemma were encountered. Upon landing Tower re-asked if the masks in the passenger cabin had deployed; and again we stated 'NO'. We also stated that all passengers were calm and no emergency services were needed. We taxied off the runway and were asked again if we need emergency services and we then replied 'No'; all is well and requesting taxi to the gate. 'We were escorted by a follow me truck to the gate and were met by [a company representative]. She asked if the passenger were ok and if we were ok. We said yes all is well. The First Officer and I conducted the shutdown checklist then allowed the passengers to deplane the aircraft after given the thumbs up by the [company representative]. I then contacted Dispatch and debriefed her on the event. After the debrief; I then contacted Maintenance for all the write-ups. Then was contacted by the Duty Manager and finally by the Chief Pilot on duty. I then conducted a debrief with the crew. No further incident occurred and then later on we departed ZZZ1 after with a flight extension and all maintenance actions were performed on the aircraft. We return to ZZZ at 8000 per the MEL and requirements. Nothing further to add.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.