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37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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Overshooting a leveloff altitude using the DC9 autoplt reminds the reporter that this equipment's performance must be monitored.
| Attributes | |
| ACN | 510400 |
| Time | |
| Date | 200105 |
| Day | Thu |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : buf.airport |
| State Reference | NY |
| Altitude | msl single value : 12000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | DC-9 Undifferentiated or Other Model |
| Flight Phase | descent : intermediate altitude |
| Route In Use | arrival : profile descent |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 51 flight time total : 4050 flight time type : 50 |
| ASRS Report | 510400 |
| Events | |
| Anomaly | aircraft equipment problem : less severe altitude deviation : overshoot non adherence : clearance |
| Resolutory Action | flight crew : returned to assigned altitude |
| Supplementary | |
| Problem Areas | Aircraft Flight Crew Human Performance |
| Primary Problem | Flight Crew Human Performance |
Narrative:
We were directed to descend down to 12000 ft. I was descending using the autoplt at 1000 FPM. I leveled off the aircraft at 12000 ft using the autoplt. I thought the aircraft was level, but soon after the plane kept descending as I picked up my charts. As I looked up again, I found the aircraft still descending. At the time I corrected the problem, and started to climb, we were at 11700 ft MSL. We were 300 ft low for about 7 seconds. The DC9 has a very old autoplt and tends to lag when using the autoplt. The autoplt doesn't capture altitudes, so monitoring the autoplt is very important.
Original NASA ASRS Text
Title: OVERSHOOTING A LEVELOFF ALT USING THE DC9 AUTOPLT REMINDS THE RPTR THAT THIS EQUIP'S PERFORMANCE MUST BE MONITORED.
Narrative: WE WERE DIRECTED TO DSND DOWN TO 12000 FT. I WAS DSNDING USING THE AUTOPLT AT 1000 FPM. I LEVELED OFF THE ACFT AT 12000 FT USING THE AUTOPLT. I THOUGHT THE ACFT WAS LEVEL, BUT SOON AFTER THE PLANE KEPT DSNDING AS I PICKED UP MY CHARTS. AS I LOOKED UP AGAIN, I FOUND THE ACFT STILL DSNDING. AT THE TIME I CORRECTED THE PROB, AND STARTED TO CLB, WE WERE AT 11700 FT MSL. WE WERE 300 FT LOW FOR ABOUT 7 SECONDS. THE DC9 HAS A VERY OLD AUTOPLT AND TENDS TO LAG WHEN USING THE AUTOPLT. THE AUTOPLT DOESN'T CAPTURE ALTS, SO MONITORING THE AUTOPLT IS VERY IMPORTANT.
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.