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B757-200 crew got on the back side of the power curve, at FL410, and with slowing airspeed, had to descend to prevent a stall.
| Attributes | |
| ACN | 632231 |
| Time | |
| Date | 200409 |
| Day | Sun |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | navaid : tcc.vortac |
| State Reference | NM |
| Altitude | msl bound lower : 37000 msl bound upper : 41000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zab.artcc tower : apa.tower |
| Operator | common carrier : air carrier |
| Make Model Name | B757-200 |
| 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 : first officer |
| Qualification | pilot : flight engineer pilot : atp |
| Experience | flight time last 90 days : 325 flight time total : 6931 flight time type : 2761 |
| ASRS Report | 632231 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 210 flight time total : 9900 flight time type : 3120 |
| ASRS Report | 632230 |
| Events | |
| Anomaly | conflict : airborne less severe non adherence : required legal separation non adherence : published procedure non adherence : far non adherence : company policies other anomaly |
| Independent Detector | aircraft equipment other aircraft equipment : air speed indicators stall buffett other flight crewa other flight crewb |
| Resolutory Action | controller : provided flight assist flight crew : declared emergency flight crew : regained aircraft control |
| Miss Distance | horizontal : 24000 vertical : 600 |
| Supplementary | |
| Problem Areas | Flight Crew Human Performance |
| Primary Problem | Flight Crew Human Performance |
Narrative:
At FL410, aircraft airspeed decayed to below 200 KIAS, stall buffet onset began. Autothrottles were engaged. PF disengaged autothrottles and manually advanced throttles forward. PNF tried to contact the ATC center controller 3 or 4 times to request a descent. Eventually contact was made and the descent was denied due to traffic at FL390. PNF declared an emergency due to the airspeed not accelerating. ATC called traffic's location and PF visually acquired traffic and started a descent. ATC assigned a 30 degree turn into the direction of traffic. PF turned a maximum of 10 degrees right to avoid traffic and preserve lift on wing. Airspeed increased, and the descent was stopped reaching FL370 assigned altitude by ATC. No further malfunction of system noted. Flight continued.
Original NASA ASRS Text
Title: B757-200 CREW GOT ON THE BACK SIDE OF THE PWR CURVE, AT FL410, AND WITH SLOWING AIRSPD, HAD TO DSND TO PREVENT A STALL.
Narrative: AT FL410, ACFT AIRSPD DECAYED TO BELOW 200 KIAS, STALL BUFFET ONSET BEGAN. AUTOTHROTTLES WERE ENGAGED. PF DISENGAGED AUTOTHROTTLES AND MANUALLY ADVANCED THROTTLES FORWARD. PNF TRIED TO CONTACT THE ATC CTR CTLR 3 OR 4 TIMES TO REQUEST A DSCNT. EVENTUALLY CONTACT WAS MADE AND THE DSCNT WAS DENIED DUE TO TFC AT FL390. PNF DECLARED AN EMER DUE TO THE AIRSPD NOT ACCELERATING. ATC CALLED TFC'S LOCATION AND PF VISUALLY ACQUIRED TFC AND STARTED A DSCNT. ATC ASSIGNED A 30 DEG TURN INTO THE DIRECTION OF TFC. PF TURNED A MAX OF 10 DEGS R TO AVOID TFC AND PRESERVE LIFT ON WING. AIRSPD INCREASED, AND THE DSCNT WAS STOPPED REACHING FL370 ASSIGNED ALT BY ATC. NO FURTHER MALFUNCTION OF SYS NOTED. FLT CONTINUED.
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.