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37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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L1011 maintaining FL350 lost control of the cabin pressure and requested lower altitude. No emergency declared. Cleared to descend to FL240. Got TCASII RA to climb and unable to stop descent made a climbing left turn to avoid the air carrier maintaining FL330. Controller issued traffic to air carrier at FL330 and conflict ended.
| Attributes | |
| ACN | 350214 |
| Time | |
| Date | 199610 |
| Day | Mon |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | atc facility : crg |
| State Reference | FL |
| Altitude | msl bound lower : 32500 msl bound upper : 35000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | artcc : zjx |
| Operator | common carrier : air carrier |
| Make Model Name | L-1011 Tri-Star All Series |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other |
| Flight Phase | descent other |
| Flight Plan | IFR |
| Aircraft 2 | |
| Operator | common carrier : air carrier |
| Make Model Name | Commercial Fixed Wing |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : second officer |
| Qualification | pilot : instrument pilot : flight engineer pilot : commercial |
| Experience | flight time last 90 days : 200 flight time total : 7300 flight time type : 4900 |
| ASRS Report | 350214 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : instrument pilot : flight engineer pilot : cfi pilot : commercial |
| Experience | flight time last 90 days : 210 flight time total : 18000 flight time type : 3035 |
| ASRS Report | 350209 |
| Events | |
| Anomaly | conflict : airborne less severe non adherence : required legal separation non adherence : far non adherence : published procedure |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified |
| Resolutory Action | flight crew : took evasive action other |
| Consequence | Other |
| Miss Distance | horizontal : 6000 vertical : 0 |
| Supplementary | |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error |
Narrative:
Air-conditioning duct blew at FL350. Cabin pressurization began climbing at 1100 FPM with all outflow valves closed. Captain asked for descent and was cleared to FL240. Descending through FL335, TCASII indicated an RA with 'climb, climb.' checking aircraft location on TCASII, first officer noticed an aircraft just to the right of our aircraft. Captain began climbing left turn, bottoming out at FL325, then climbing back up to FL335, at which time the RA was over. ZJX (which initially cleared us to descend to FL240) then stated to an air carrier flight (who was inquiring about his RA) that an L1011 was descending due to a pressurization problem. No emergency was declared. We continued down to FL180, at which time cabin pressurization control was regained. ATC put us in an extremely hazardous position by giving us permission to descend, even though the other aircraft was nearby, and at FL330, only 2000 ft below us. This was not an emergency descent, yet ATC apparently thought that we needed to descend, without regard to standard separation.
Original NASA ASRS Text
Title: L1011 MAINTAINING FL350 LOST CTL OF THE CABIN PRESSURE AND REQUESTED LOWER ALT. NO EMER DECLARED. CLRED TO DSND TO FL240. GOT TCASII RA TO CLB AND UNABLE TO STOP DSCNT MADE A CLBING L TURN TO AVOID THE ACR MAINTAINING FL330. CTLR ISSUED TFC TO ACR AT FL330 AND CONFLICT ENDED.
Narrative: AIR-CONDITIONING DUCT BLEW AT FL350. CABIN PRESSURIZATION BEGAN CLBING AT 1100 FPM WITH ALL OUTFLOW VALVES CLOSED. CAPT ASKED FOR DSCNT AND WAS CLRED TO FL240. DSNDING THROUGH FL335, TCASII INDICATED AN RA WITH 'CLB, CLB.' CHKING ACFT LOCATION ON TCASII, FO NOTICED AN ACFT JUST TO THE R OF OUR ACFT. CAPT BEGAN CLBING L TURN, BOTTOMING OUT AT FL325, THEN CLBING BACK UP TO FL335, AT WHICH TIME THE RA WAS OVER. ZJX (WHICH INITIALLY CLRED US TO DSND TO FL240) THEN STATED TO AN ACR FLT (WHO WAS INQUIRING ABOUT HIS RA) THAT AN L1011 WAS DSNDING DUE TO A PRESSURIZATION PROB. NO EMER WAS DECLARED. WE CONTINUED DOWN TO FL180, AT WHICH TIME CABIN PRESSURIZATION CTL WAS REGAINED. ATC PUT US IN AN EXTREMELY HAZARDOUS POS BY GIVING US PERMISSION TO DSND, EVEN THOUGH THE OTHER ACFT WAS NEARBY, AND AT FL330, ONLY 2000 FT BELOW US. THIS WAS NOT AN EMER DSCNT, YET ATC APPARENTLY THOUGHT THAT WE NEEDED TO DSND, WITHOUT REGARD TO STANDARD SEPARATION.
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.