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Flight crew of a DHC8 climbed above assigned cruise altitude due to the autoplt not capturing the return to assigned altitude and due to the captain's misunderstanding of an ATC TA.
| Attributes | |
| ACN | 339700 |
| Time | |
| Date | 199606 |
| Day | Thu |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : sbj |
| State Reference | NJ |
| Altitude | msl bound lower : 12000 msl bound upper : 12000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : vhhk |
| Operator | common carrier : air carrier |
| Make Model Name | Dash 8 Series Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise other |
| Route In Use | enroute airway : zny |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | other other : other pilot : atp pilot : cfi |
| Experience | flight time last 90 days : 240 flight time total : 6300 flight time type : 2800 |
| ASRS Report | 339700 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude 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:
After getting a TA from ZNY, the captain (PF) mistook it for a climb clearance from 12000 ft to 14000 ft. He dialed 14000 ft into the altitude box and set the autoplt for a climb. He confirmed the clearance with me. However, I told him there was no clearance, and to maintain 12000 ft. By now we had climbed 50 ft. He reset the autoplt for 12000 ft, and it recaptured. However, approximately 1 min later the altitude alerter went off signaling we had deviated 250 ft. The capture of our autoplt must have disengaged. We descended immediately back to 12000 ft. There was no traffic conflict. ATC never mentioned it. I don't know why the autoplt captured and then canceled its altitude hold. Probably more vigilance would have caught it sooner.
Original NASA ASRS Text
Title: FLC OF A DHC8 CLBED ABOVE ASSIGNED CRUISE ALT DUE TO THE AUTOPLT NOT CAPTURING THE RETURN TO ASSIGNED ALT AND DUE TO THE CAPT'S MISUNDERSTANDING OF AN ATC TA.
Narrative: AFTER GETTING A TA FROM ZNY, THE CAPT (PF) MISTOOK IT FOR A CLB CLRNC FROM 12000 FT TO 14000 FT. HE DIALED 14000 FT INTO THE ALT BOX AND SET THE AUTOPLT FOR A CLB. HE CONFIRMED THE CLRNC WITH ME. HOWEVER, I TOLD HIM THERE WAS NO CLRNC, AND TO MAINTAIN 12000 FT. BY NOW WE HAD CLBED 50 FT. HE RESET THE AUTOPLT FOR 12000 FT, AND IT RECAPTURED. HOWEVER, APPROX 1 MIN LATER THE ALT ALERTER WENT OFF SIGNALING WE HAD DEVIATED 250 FT. THE CAPTURE OF OUR AUTOPLT MUST HAVE DISENGAGED. WE DSNDED IMMEDIATELY BACK TO 12000 FT. THERE WAS NO TFC CONFLICT. ATC NEVER MENTIONED IT. I DON'T KNOW WHY THE AUTOPLT CAPTURED AND THEN CANCELED ITS ALT HOLD. PROBABLY MORE VIGILANCE WOULD HAVE CAUGHT IT SOONER.
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.