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37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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CE550 aircraft. In descent to assigned altitude either the flight crew inadvertently turned off the altitude preselect or some other mode change dropped the preselect, but flight crew caught the altitude deviation after the aircraft had descended 440 ft. Below assigned. Aircraft was flown back to assigned.
| Attributes | |
| ACN | 357410 |
| Time | |
| Date | 199701 |
| Day | Wed |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : psp |
| State Reference | CA |
| Altitude | msl bound lower : 25400 msl bound upper : 26000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zla tower : ewr |
| Operator | general aviation : personal |
| Make Model Name | Citation II/SP |
| Operating Under FAR Part | Part 91 |
| Navigation In Use | Other Other |
| Flight Phase | cruise other descent other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | Other |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : cfi |
| Experience | flight time last 90 days : 70 flight time total : 10000 flight time type : 700 |
| ASRS Report | 357410 |
| Person 2 | |
| Affiliation | Other |
| Function | flight crew : first officer |
| Qualification | pilot : instrument pilot : commercial |
| Experience | flight time last 90 days : 100 flight time total : 1750 flight time type : 800 |
| ASRS Report | 357412 |
| Events | |
| Anomaly | altitude deviation : overshoot non adherence : clearance |
| Independent Detector | other flight crewa |
| Resolutory Action | flight crew : returned to intended course or assigned course |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
Descending on autoplt with altitude capture selected aircraft failed to level at FL260 as assigned, went down to 440 ft below. Copilot caught this before I did, called it out. I climbed to FL260. I immediately reengaged autoplt at this altitude. This was a case of automation seduction. I don't know if one of us inadvertently turned off the altitude preselect or it just failed (though it worked during the remainder of day's flying). Anyway no more trust -- 'let george do it' but watch the little sucker.
Original NASA ASRS Text
Title: CE550 ACFT. IN DSCNT TO ASSIGNED ALT EITHER THE FLC INADVERTENTLY TURNED OFF THE ALT PRESELECT OR SOME OTHER MODE CHANGE DROPPED THE PRESELECT, BUT FLC CAUGHT THE ALTDEV AFTER THE ACFT HAD DSNDED 440 FT. BELOW ASSIGNED. ACFT WAS FLOWN BACK TO ASSIGNED.
Narrative: DSNDING ON AUTOPLT WITH ALT CAPTURE SELECTED ACFT FAILED TO LEVEL AT FL260 AS ASSIGNED, WENT DOWN TO 440 FT BELOW. COPLT CAUGHT THIS BEFORE I DID, CALLED IT OUT. I CLBED TO FL260. I IMMEDIATELY REENGAGED AUTOPLT AT THIS ALT. THIS WAS A CASE OF AUTOMATION SEDUCTION. I DON'T KNOW IF ONE OF US INADVERTENTLY TURNED OFF THE ALT PRESELECT OR IT JUST FAILED (THOUGH IT WORKED DURING THE REMAINDER OF DAY'S FLYING). ANYWAY NO MORE TRUST -- 'LET GEORGE DO IT' BUT WATCH THE LITTLE SUCKER.
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.