 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
B737-700 flight crew reported an uneventful emergency descent & diversion due to a loss of pressurization during cruise.
| Attributes | |
| ACN | 1738959 |
| Time | |
| Date | 202004 |
| Local Time Of Day | 0601-1200 |
| Place | |
| Locale Reference | ZZZ.ARTCC |
| State Reference | US |
| Aircraft 1 | |
| Make Model Name | B737-700 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Cruise |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | Pressurization Control System |
| Person 1 | |
| Function | Pilot Not Flying Captain |
| Qualification | Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) |
| Experience | Flight Crew Last 90 Days 367 Flight Crew Type 10000 |
| Person 2 | |
| Function | First Officer Pilot Flying |
| Qualification | Flight Crew Multiengine Flight Crew Instrument Flight Crew Air Transport Pilot (ATP) |
| Experience | Flight Crew Last 90 Days 120 |
| Events | |
| Anomaly | Aircraft Equipment Problem Critical |
Narrative:
First officer (first officer) and I noticed a series of 'thumps' while in cruise at FL410. We suspected pressurization and noticed cabin climbing slowly at 500 fpm. Cabin did not stabilize and was just over 9000 feet. We decided to start a normal but rapid descent to a lower cruise altitude. We got the cabin altitude aural alert and warning light during the descent. Accomplished qrc/QRH; which required an emergency descent and deployment of cabin O2 masks. Notified ATC and got clearance to 14;000 feet. Passing about FL230 we noticed cabin was below 9000 feet and stable. We stopped descent at FL210 and diverted to ZZZ. Checked with F/as (flight attendants) to make sure there were no injuries and to advise that they and passengers could remove O2 masks. The rest of flight was uneventful. Preventative measures: first officer suggested that we start down as soon as we saw the cabin climbing after the thumps. I wanted to see if cabin would stabilize since the rate was slow. If we started down earlier; we may have avoided the emergency descent/masks since the cabin stabilized at FL230.
Original NASA ASRS Text
Title: B737-700 flight crew reported an uneventful emergency descent & diversion due to a loss of pressurization during cruise.
Narrative: F/O (First Officer) and I noticed a series of 'thumps' while in cruise at FL410. We suspected pressurization and noticed cabin climbing slowly at 500 fpm. Cabin did not stabilize and was just over 9000 feet. We decided to start a normal but rapid descent to a lower cruise altitude. We got the Cabin Altitude aural alert and warning light during the descent. Accomplished QRC/QRH; which required an emergency descent and deployment of cabin O2 masks. Notified ATC and got clearance to 14;000 feet. Passing about FL230 we noticed cabin was below 9000 feet and stable. We stopped descent at FL210 and diverted to ZZZ. Checked with F/As (Flight Attendants) to make sure there were no injuries and to advise that they and passengers could remove O2 masks. The rest of flight was uneventful. Preventative Measures: F/O suggested that we start down as soon as we saw the cabin climbing after the thumps. I wanted to see if cabin would stabilize since the rate was slow. If we started down earlier; we may have avoided the emergency descent/masks since the cabin stabilized at FL230.
Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.