 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
An air carrier MD11 flight crew slowed, at controller request, to a speed that was near alpha speed for the aircraft's confign and then entered a turn. The increased bank angle caused the autoflt system to react as it should to prevent a stall by having the autothrottles go to full power which then caused the aircraft to exceed normal autoplt pitch correction forces and the aircraft started to climb.
| Attributes | |
| ACN | 386371 |
| Time | |
| Date | 199711 |
| Day | Thu |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : mia |
| State Reference | FL |
| Altitude | msl bound lower : 9000 msl bound upper : 9500 |
| Environment | |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : mia tower : dfw |
| Operator | common carrier : air carrier |
| Make Model Name | MD-11 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other Other |
| Flight Phase | cruise other descent other |
| Route In Use | enroute : on vectors |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : instrument pilot : commercial |
| ASRS Report | 386371 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| ASRS Report | 386680 |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : far other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other flight crewa |
| Resolutory Action | flight crew : returned to intended course or assigned course other |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
During descent into mia we were cleared from 10000 ft to 9000 ft and asked to slow to 210 KTS. Just prior to altitude capture and at speed of 210 KTS clean, we were given a turn from 180 degree heading to 270 degrees. As we started to turn, we approached v-min and extended slats. At the same time, due to alpha conditions, power came up and aircraft started to climb. We disconnected autoplt and autothrottles and descended back to 9000 ft. The climb was to 9500 ft. Controller made no mention of the altitude excursion. We continued the approach without any further problems.
Original NASA ASRS Text
Title: AN ACR MD11 FLC SLOWED, AT CTLR REQUEST, TO A SPD THAT WAS NEAR ALPHA SPD FOR THE ACFT'S CONFIGN AND THEN ENTERED A TURN. THE INCREASED BANK ANGLE CAUSED THE AUTOFLT SYS TO REACT AS IT SHOULD TO PREVENT A STALL BY HAVING THE AUTOTHROTTLES GO TO FULL PWR WHICH THEN CAUSED THE ACFT TO EXCEED NORMAL AUTOPLT PITCH CORRECTION FORCES AND THE ACFT STARTED TO CLB.
Narrative: DURING DSCNT INTO MIA WE WERE CLRED FROM 10000 FT TO 9000 FT AND ASKED TO SLOW TO 210 KTS. JUST PRIOR TO ALT CAPTURE AND AT SPD OF 210 KTS CLEAN, WE WERE GIVEN A TURN FROM 180 DEG HDG TO 270 DEGS. AS WE STARTED TO TURN, WE APCHED V-MIN AND EXTENDED SLATS. AT THE SAME TIME, DUE TO ALPHA CONDITIONS, PWR CAME UP AND ACFT STARTED TO CLB. WE DISCONNECTED AUTOPLT AND AUTOTHROTTLES AND DSNDED BACK TO 9000 FT. THE CLB WAS TO 9500 FT. CTLR MADE NO MENTION OF THE ALT EXCURSION. WE CONTINUED THE APCH WITHOUT ANY FURTHER PROBS.
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.