 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Air carrier large transport experiences unnoticed and unexplained altitude loss during flap retraction and speed increase portion of initial climb.
| Attributes | |
| ACN | 133905 |
| Time | |
| Date | 199001 |
| Day | Mon |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | airport : dtw |
| State Reference | MI |
| Altitude | agl bound lower : 600 agl bound upper : 1000 |
| Environment | |
| Flight Conditions | IMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tower : dtw |
| Operator | common carrier : air carrier |
| Make Model Name | Large Transport, Low Wing, 2 Turbojet Eng |
| Navigation In Use | Other Other |
| Flight Phase | climbout : intermediate altitude climbout : initial |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : flight engineer pilot : instrument pilot : commercial pilot : atp |
| Experience | flight time last 90 days : 250 flight time total : 9000 flight time type : 900 |
| ASRS Report | 133905 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Events | |
| Anomaly | aircraft equipment problem : critical other anomaly other |
| Independent Detector | other flight crewa |
| Resolutory Action | flight crew : returned to intended course or assigned course |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Ambiguous |
| Air Traffic Incident | other |
Narrative:
As aircraft climbed through 1000' AGL, clean up started and power was reduced on the thrust management computer (tmc). During clean up and power reduction, abnormal nose down trim was felt. In the process of sorting things out (climb, clean up, heading change, abnormal trim), the aircraft descended 300-400'. The autothrottles were coming back. The warning 'don't sink' on the GPWS went off. The first officer responded by pushing the power levers back to climb power. I pulled the nose up and resumed the climb profile. I still don't know if the trim ran away, autothrottles malfunctioned (nose down trim), or if I just plain screwed up. 27 yrs in aviation, I've never had any problem. I have been going through some family crisis and emotions have certainly been frayed. Watch out for complacency in the glass cockpit!
Original NASA ASRS Text
Title: ACR LGT EXPERIENCES UNNOTICED AND UNEXPLAINED ALT LOSS DURING FLAP RETRACTION AND SPEED INCREASE PORTION OF INITIAL CLIMB.
Narrative: AS ACFT CLBED THROUGH 1000' AGL, CLEAN UP STARTED AND PWR WAS REDUCED ON THE THRUST MGMNT COMPUTER (TMC). DURING CLEAN UP AND PWR REDUCTION, ABNORMAL NOSE DOWN TRIM WAS FELT. IN THE PROCESS OF SORTING THINGS OUT (CLB, CLEAN UP, HDG CHANGE, ABNORMAL TRIM), THE ACFT DSNDED 300-400'. THE AUTOTHROTTLES WERE COMING BACK. THE WARNING 'DON'T SINK' ON THE GPWS WENT OFF. THE F/O RESPONDED BY PUSHING THE PWR LEVERS BACK TO CLB PWR. I PULLED THE NOSE UP AND RESUMED THE CLB PROFILE. I STILL DON'T KNOW IF THE TRIM RAN AWAY, AUTOTHROTTLES MALFUNCTIONED (NOSE DOWN TRIM), OR IF I JUST PLAIN SCREWED UP. 27 YRS IN AVIATION, I'VE NEVER HAD ANY PROB. I HAVE BEEN GOING THROUGH SOME FAMILY CRISIS AND EMOTIONS HAVE CERTAINLY BEEN FRAYED. WATCH OUT FOR COMPLACENCY IN THE GLASS COCKPIT!
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.