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Preprogramming an expected crossing altitude in the autoflt system coupled with other distractions leads to an altitude excursion that is accepted by the ARTCC radar controller.
| Attributes | |
| ACN | 525090 |
| Time | |
| Date | 200109 |
| Day | Wed |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | intersection : ridgy |
| State Reference | MD |
| Altitude | msl bound lower : 24000 msl bound upper : 27000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | B737-300 |
| Flight Phase | cruise : enroute altitude change |
| Route In Use | arrival star : rbv 1 |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 150 flight time total : 21000 flight time type : 6000 |
| ASRS Report | 525090 |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : published procedure |
| Resolutory Action | controller : issued new clearance controller : issued advisory |
| Supplementary | |
| Problem Areas | Flight Crew Human Performance |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
Cruising FL220 en route jax-ewr expected clearance to cross ridgy at FL240. I had preloaded this in the FMC. First officer was communicating with company as aircraft approached ridgy. VNAV had been selected. As we approached, throttles began to retard, the aircraft did not begin to descend. I clicked off the autoplt and descended to FL240. Center asked my altitude and I responded 'FL240 do you show something else?' response was 'no, I thought I had stopped you at FL270. It's ok, stay where you are.' I will not again preload 'expect' altitude in the FMC. Contributing to this was first officer on radio with company, and our en route discussions of current events.
Original NASA ASRS Text
Title: PREPROGRAMMING AN EXPECTED XING ALT IN THE AUTOFLT SYS COUPLED WITH OTHER DISTRACTIONS LEADS TO AN ALT EXCURSION THAT IS ACCEPTED BY THE ARTCC RADAR CTLR.
Narrative: CRUISING FL220 ENRTE JAX-EWR EXPECTED CLRNC TO CROSS RIDGY AT FL240. I HAD PRELOADED THIS IN THE FMC. FO WAS COMMUNICATING WITH COMPANY AS ACFT APCHED RIDGY. VNAV HAD BEEN SELECTED. AS WE APCHED, THROTTLES BEGAN TO RETARD, THE ACFT DID NOT BEGIN TO DSND. I CLICKED OFF THE AUTOPLT AND DSNDED TO FL240. CTR ASKED MY ALT AND I RESPONDED 'FL240 DO YOU SHOW SOMETHING ELSE?' RESPONSE WAS 'NO, I THOUGHT I HAD STOPPED YOU AT FL270. IT'S OK, STAY WHERE YOU ARE.' I WILL NOT AGAIN PRELOAD 'EXPECT' ALT IN THE FMC. CONTRIBUTING TO THIS WAS FO ON RADIO WITH COMPANY, AND OUR ENRTE DISCUSSIONS OF CURRENT EVENTS.
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.