37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Attributes | |
ACN | 397602 |
Time | |
Date | 199803 |
Day | Fri |
Local Time Of Day | 0601 To 1200 |
Place | |
Locale Reference | airport : lim |
State Reference | FO |
Altitude | msl bound lower : 1700 msl bound upper : 2000 |
Environment | |
Light | Daylight |
Aircraft 1 | |
Controlling Facilities | tracon : lim |
Operator | common carrier : air carrier |
Make Model Name | B757 Undifferentiated or Other Model |
Operating Under FAR Part | Part 121 |
Navigation In Use | Other Other |
Flight Phase | descent other |
Route In Use | arrival other arrival star : star enroute airway : lim |
Flight Plan | IFR |
Person 1 | |
Affiliation | company : air carrier |
Function | flight crew : captain oversight : pic |
Qualification | pilot : atp |
ASRS Report | 397602 |
Person 2 | |
Affiliation | company : air carrier |
Function | flight crew : first officer |
Qualification | pilot : commercial pilot : instrument |
Events | |
Anomaly | aircraft equipment problem : critical altitude deviation : overshoot non adherence : clearance non adherence : published procedure |
Independent Detector | aircraft equipment other aircraft equipment : unspecified other flight crewa |
Resolutory Action | flight crew : became reoriented flight crew : declared emergency flight crew : returned to intended course or assigned course |
Consequence | Other |
Supplementary | |
Primary Problem | Aircraft |
Air Traffic Incident | Pilot Deviation |
Narrative:
On a classic high speed descent executing the sls one arrival. Descending to 2000 ft by sigas, aircraft began to lose cabin pressure at rates of 2000-3000 ft. This was preceded by loud air noise in the cockpit. No EICAS message or aural warnings, switched to mode 2 with no effect. Then went to manual with no effect. I was hand flying and becoming preoccupied with the problem. Fly the airplane stupid. I settled approximately 100 ft below 2000 ft. Also missed the transition altitude of 4000 ft, reset at 29.77. Now almost 300 ft low. Corrected immediately...still confused at problem...decided that no threat existed other than discomfort and ears popping. Pressed on and landed without any further attempt at a correction. On ground flight attendants said a lot of air noise and curtains waving. No complaints from passenger. Wrote up in log. Mechanics could not duplicate. Aircraft went to dfw and was tracked, no problem. I figure the air/ground logic change cured the problem for now. Could not understand the problem with no EICAS. I do not believe it was airframe. Either fault with outflow or ee cooling. Moral to story: captain designates who will work the problem and who will fly the aircraft. Seems I've heard that somewhere before, about 500 times.
Original NASA ASRS Text
Title: B757 ACFT IN HIGH SPD DSCNT STARTED LOSING CABIN PRESSURE. FLC ATTEMPTED TO CTL IT TO NO AVAIL. THE DISTR RESULTED IN DSCNT BELOW ASSIGNED ALT. ACFT CHKED BY MECHS AND NO KNOWN CAUSE FOUND.
Narrative: ON A CLASSIC HIGH SPD DSCNT EXECUTING THE SLS ONE ARR. DSNDING TO 2000 FT BY SIGAS, ACFT BEGAN TO LOSE CABIN PRESSURE AT RATES OF 2000-3000 FT. THIS WAS PRECEDED BY LOUD AIR NOISE IN THE COCKPIT. NO EICAS MESSAGE OR AURAL WARNINGS, SWITCHED TO MODE 2 WITH NO EFFECT. THEN WENT TO MANUAL WITH NO EFFECT. I WAS HAND FLYING AND BECOMING PREOCCUPIED WITH THE PROB. FLY THE AIRPLANE STUPID. I SETTLED APPROX 100 FT BELOW 2000 FT. ALSO MISSED THE TRANSITION ALT OF 4000 FT, RESET AT 29.77. NOW ALMOST 300 FT LOW. CORRECTED IMMEDIATELY...STILL CONFUSED AT PROB...DECIDED THAT NO THREAT EXISTED OTHER THAN DISCOMFORT AND EARS POPPING. PRESSED ON AND LANDED WITHOUT ANY FURTHER ATTEMPT AT A CORRECTION. ON GND FLT ATTENDANTS SAID A LOT OF AIR NOISE AND CURTAINS WAVING. NO COMPLAINTS FROM PAX. WROTE UP IN LOG. MECHS COULD NOT DUPLICATE. ACFT WENT TO DFW AND WAS TRACKED, NO PROB. I FIGURE THE AIR/GND LOGIC CHANGE CURED THE PROB FOR NOW. COULD NOT UNDERSTAND THE PROB WITH NO EICAS. I DO NOT BELIEVE IT WAS AIRFRAME. EITHER FAULT WITH OUTFLOW OR EE COOLING. MORAL TO STORY: CAPT DESIGNATES WHO WILL WORK THE PROB AND WHO WILL FLY THE ACFT. SEEMS I'VE HEARD THAT SOMEWHERE BEFORE, ABOUT 500 TIMES.
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.