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B737 flight crew experiences a cabin altitude warning horn passing through FL210 during climb. Crew is able to control the outflow valve manually and continue to destination. The aircraft had a history of pressurization problems.
| Attributes | |
| ACN | 925583 |
| Time | |
| Date | 201012 |
| Local Time Of Day | 1801-2400 |
| Place | |
| Locale Reference | ZZZ.Airport |
| State Reference | US |
| Environment | |
| Flight Conditions | VMC |
| Light | Night |
| Aircraft 1 | |
| Make Model Name | B737-300 |
| Flight Phase | Climb |
| Component | |
| Aircraft Component | Pressurization Outflow Valve |
| Person 1 | |
| Function | First Officer |
| Experience | Flight Crew Last 90 Days 189 Flight Crew Type 189 |
| Person 2 | |
| Function | Captain |
| Qualification | Flight Crew Air Transport Pilot (ATP) |
| Experience | Flight Crew Last 90 Days 189 |
| Events | |
| Anomaly | Aircraft Equipment Problem Less Severe |
Narrative:
Climbing through FL210 the intermittent warning horn sounded. I donned my oxygen mask and configured the radios for communication. I reported to ATC that we had a pressurization issue and needed to stop climbing. The captain tried to regain cabin altitude control by selecting the (analog) mode first to standby; and when that failed; to manual. The outflow valve quickly moved towards the close position and control was quickly regained and the cabin altitude descended rapidly. I read the appropriate QRH checklists and we left the mode controller in manual. ATC initially re-cleared us to 10;000 ft; but once the pressurization control was regained we decided to level off at FL230 and remained there for the rest of the flight. Adjustments were made to maintain the optimal cabin altitude for our flight level and also while descending and landing. Note: passing through 10;000 ft; the climb checklist was accomplished and the aircraft seemed to be pressurizing normally.we were running approximately five hours late and we were given an aircraft from the hangar; which had previously been written up for the same type of malfunction at FL260. The corrective action showed that the outflow valve had just been replaced so we were cognizant of the plane's recent history and it allowed for a more timely reaction to the event. However; it's clear the original problem was not resolved.
Original NASA ASRS Text
Title: B737 flight crew experiences a cabin altitude warning horn passing through FL210 during climb. Crew is able to control the outflow valve manually and continue to destination. The aircraft had a history of pressurization problems.
Narrative: Climbing through FL210 the intermittent warning horn sounded. I donned my oxygen mask and configured the radios for communication. I reported to ATC that we had a pressurization issue and needed to stop climbing. The Captain tried to regain cabin altitude control by selecting the (analog) mode first to standby; and when that failed; to manual. The outflow valve quickly moved towards the close position and control was quickly regained and the cabin altitude descended rapidly. I read the appropriate QRH checklists and we left the mode controller in manual. ATC initially re-cleared us to 10;000 FT; but once the pressurization control was regained we decided to level off at FL230 and remained there for the rest of the flight. Adjustments were made to maintain the optimal cabin altitude for our flight level and also while descending and landing. Note: Passing through 10;000 FT; the Climb Checklist was accomplished and the aircraft seemed to be pressurizing normally.We were running approximately five hours late and we were given an aircraft from the hangar; which had previously been written up for the same type of malfunction at FL260. The corrective action showed that the outflow valve had just been replaced so we were cognizant of the plane's recent history and it allowed for a more timely reaction to the event. However; it's clear the original problem was not resolved.
Data retrieved from NASA's ASRS site as of April 2012 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.