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Captain of a cargo B727 made an emergency descent after malfunction of the pressurization system caused the cabin altitude to climb. The flight crew were unable to obtain descent clearance until after starting their descent due to frequency congestion.
| Attributes | |
| ACN | 458249 |
| Time | |
| Date | 199912 |
| Day | Fri |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | airport : mem.airport |
| State Reference | TN |
| Altitude | msl bound lower : 28400 msl single value : 29000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | artcc : zme.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | B727 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise : level cruise : enroute altitude change |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 50 flight time total : 17000 flight time type : 3000 |
| ASRS Report | 458249 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : multi engine pilot : commercial pilot : instrument |
| Events | |
| Anomaly | aircraft equipment problem : critical altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly |
| Independent Detector | aircraft equipment other aircraft equipment : pressurization other flight crewa other flight crewb other other : 3 |
| Resolutory Action | flight crew : declared emergency other |
| Consequence | other |
| Supplementary | |
| Problem Areas | Aircraft Flight Crew Human Performance |
| Primary Problem | Aircraft |
Narrative:
Aircraft experienced fumes in cockpit. Fumes were resolved by securing right air conditioning pack, leaving aircraft operating on 1 pack. Aircraft could not maintain adequate pressurization on 1 pack and crew noticed altitude was climbing through 9500 ft at 400-500 FPM. Crew made several attempts to contact center for lower altitude. Frequency was quite congested and first few attempts were not answered. On final attempt at contact, center directed crew to 'stand by.' captain cleared flight path below aircraft, turned on landing lights, and initiated descent without clearance. Within seconds, radio contact was established (missing about FL284) and center progressively cleared aircraft to lower altitudes. Pressurization was finally ctlable (9500 ft cabin altitude) at FL180. Flight continued to destination at FL180.
Original NASA ASRS Text
Title: CAPT OF A CARGO B727 MADE AN EMER DSCNT AFTER MALFUNCTION OF THE PRESSURIZATION SYS CAUSED THE CABIN ALT TO CLB. THE FLC WERE UNABLE TO OBTAIN DSCNT CLRNC UNTIL AFTER STARTING THEIR DSCNT DUE TO FREQ CONGESTION.
Narrative: ACFT EXPERIENCED FUMES IN COCKPIT. FUMES WERE RESOLVED BY SECURING R AIR CONDITIONING PACK, LEAVING ACFT OPERATING ON 1 PACK. ACFT COULD NOT MAINTAIN ADEQUATE PRESSURIZATION ON 1 PACK AND CREW NOTICED ALT WAS CLBING THROUGH 9500 FT AT 400-500 FPM. CREW MADE SEVERAL ATTEMPTS TO CONTACT CTR FOR LOWER ALT. FREQ WAS QUITE CONGESTED AND FIRST FEW ATTEMPTS WERE NOT ANSWERED. ON FINAL ATTEMPT AT CONTACT, CTR DIRECTED CREW TO 'STAND BY.' CAPT CLRED FLT PATH BELOW ACFT, TURNED ON LNDG LIGHTS, AND INITIATED DSCNT WITHOUT CLRNC. WITHIN SECONDS, RADIO CONTACT WAS ESTABLISHED (MISSING ABOUT FL284) AND CTR PROGRESSIVELY CLRED ACFT TO LOWER ALTS. PRESSURIZATION WAS FINALLY CTLABLE (9500 FT CABIN ALT) AT FL180. FLT CONTINUED TO DEST AT FL180.
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.