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37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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A lear 25 pilot reports a rapidly climbing cabin altitude. Resetting the circuit breaker cured the problem.
| Attributes | |
| ACN | 350040 |
| Time | |
| Date | 199610 |
| Day | Tue |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : stl |
| State Reference | MO |
| Altitude | msl bound lower : 25000 msl bound upper : 37000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zme |
| Operator | general aviation : personal |
| Make Model Name | Learjet 25 |
| Operating Under FAR Part | Part 91 |
| Flight Phase | climbout : intermediate altitude descent other other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | Other |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : cfi pilot : atp pilot : instrument |
| Experience | flight time last 90 days : 175 flight time total : 3400 flight time type : 100 |
| ASRS Report | 350040 |
| Person 2 | |
| Affiliation | Other |
| Function | flight crew : first officer |
| Qualification | pilot : commercial pilot : instrument |
| Events | |
| Anomaly | aircraft equipment problem : critical altitude deviation : excursion from assigned altitude altitude deviation : overshoot non adherence : clearance other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other flight crewa |
| Resolutory Action | controller : issued new clearance flight crew : overcame equipment problem flight crew : declared emergency |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Aircraft |
| Air Traffic Incident | other |
Narrative:
Climbing through 37000 ft for 41000 ft we began to experience a rapid increase in cabin altitude. I immediately began to descend and the copilot requested clearance for lower. We were cleared to 34000 ft. As I was dealing with handling the situation, I noticed that we had descended below 34000 ft and were flying at 33500 ft. We again requested lower and were given a turn and a frequency change. The next controller cleared us to 33000 ft and we advised that we really needed lower because we had a problem in the cabin. At this point I believe we were maintaining 33000 ft although we may have descended lower, again, inadvertently. We were then cleared to 25000 ft. During our descent, we discovered that the cabin pressure circuit breaker had popped, and when we reset it, the cabin pressure returned to normal and our flight continued uneventfully.
Original NASA ASRS Text
Title: A LEAR 25 PLT RPTS A RAPIDLY CLBING CABIN ALT. RESETTING THE CIRCUIT BREAKER CURED THE PROB.
Narrative: CLBING THROUGH 37000 FT FOR 41000 FT WE BEGAN TO EXPERIENCE A RAPID INCREASE IN CABIN ALT. I IMMEDIATELY BEGAN TO DSND AND THE COPLT REQUESTED CLRNC FOR LOWER. WE WERE CLRED TO 34000 FT. AS I WAS DEALING WITH HANDLING THE SIT, I NOTICED THAT WE HAD DSNDED BELOW 34000 FT AND WERE FLYING AT 33500 FT. WE AGAIN REQUESTED LOWER AND WERE GIVEN A TURN AND A FREQ CHANGE. THE NEXT CTLR CLRED US TO 33000 FT AND WE ADVISED THAT WE REALLY NEEDED LOWER BECAUSE WE HAD A PROB IN THE CABIN. AT THIS POINT I BELIEVE WE WERE MAINTAINING 33000 FT ALTHOUGH WE MAY HAVE DSNDED LOWER, AGAIN, INADVERTENTLY. WE WERE THEN CLRED TO 25000 FT. DURING OUR DSCNT, WE DISCOVERED THAT THE CABIN PRESSURE CIRCUIT BREAKER HAD POPPED, AND WHEN WE RESET IT, THE CABIN PRESSURE RETURNED TO NORMAL AND OUR FLT CONTINUED UNEVENTFULLY.
Data retrieved from NASA's ASRS site as of July 2007 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.