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37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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After being cleared to FL290 the PNF, verified by the PF, put FL290 in the altitude alert window. Subsequently, as the aircraft was climbing through FL290 the PNF noticed FL310 was in the altitude alerter. Neither the PF nor the PNF had changed the setting of FL290. The flight controller, when asked by the PF, confirmed they were still cleared to FL290. A 600 ft altitude excursion occurred in the process of the PNF getting the aircraft leveled at FL290. The aircraft had a number of flight guidance system discrepancies.
| Attributes | |
| ACN | 333130 |
| Time | |
| Date | 199604 |
| Day | Fri |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | atc facility : cvo |
| State Reference | OR |
| Altitude | msl bound lower : 29000 msl bound upper : 29600 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zse |
| Operator | common carrier : air carrier |
| Make Model Name | Commercial Fixed Wing |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other Other |
| Flight Phase | climbout : intermediate altitude cruise other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 180 flight time total : 16500 flight time type : 7000 |
| ASRS Report | 333130 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : commercial pilot : instrument |
| Events | |
| Anomaly | aircraft equipment problem : less severe altitude deviation : overshoot non adherence : clearance |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified |
| Resolutory Action | flight crew : overcame equipment problem flight crew : returned to intended course or assigned course |
| Consequence | faa : reviewed incident with flight crew |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
After departing sea airport and being handed over to ZSE, the aircraft was cleared to FL290, I, as the PNF, put FL290 in the altitude alert window. I then advised the PF that I was leaving the frequency to call in our departure time to our company operations, after he confirmed our altitude clearance of FL290. After calling in the departure time and returning to the frequency, I looked up at the instrument panel and saw that the aircraft was about to penetrate FL290 and that 31000 ft was now set in the altitude alert window. I asked the PF if there was a change in our altitude clearance and he informed me that there was not. I immediately disconnected both the autoplt and the autothrottles. I reduced the power and pushed the nose over to hold the altitude at FL290. We penetrated our altitude of FL290 by approximately 600 ft. While I was doing this, the first officer asked ATC what our assigned altitude was. ATC stated it as being FL290. The first officer (PF) informed me that he never put 31000 ft in the altitude alert window. We both verified FL290 when it was inserted in the altitude alert window. The aircraft had a number of additional DFGS mishaps during the flight. This system controls the automation of the aircraft. I would also like to state that on previous occasions I have observed that a digit (which is nothing more than a light) set on the DFGS panel has changed to a higher or lower number for no apparent reason.
Original NASA ASRS Text
Title: AFTER BEING CLRED TO FL290 THE PNF, VERIFIED BY THE PF, PUT FL290 IN THE ALT ALERT WINDOW. SUBSEQUENTLY, AS THE ACFT WAS CLBING THROUGH FL290 THE PNF NOTICED FL310 WAS IN THE ALT ALERTER. NEITHER THE PF NOR THE PNF HAD CHANGED THE SETTING OF FL290. THE FLT CTLR, WHEN ASKED BY THE PF, CONFIRMED THEY WERE STILL CLRED TO FL290. A 600 FT ALT EXCURSION OCCURRED IN THE PROCESS OF THE PNF GETTING THE ACFT LEVELED AT FL290. THE ACFT HAD A NUMBER OF FLT GUIDANCE SYS DISCREPANCIES.
Narrative: AFTER DEPARTING SEA ARPT AND BEING HANDED OVER TO ZSE, THE ACFT WAS CLRED TO FL290, I, AS THE PNF, PUT FL290 IN THE ALT ALERT WINDOW. I THEN ADVISED THE PF THAT I WAS LEAVING THE FREQ TO CALL IN OUR DEP TIME TO OUR COMPANY OPS, AFTER HE CONFIRMED OUR ALT CLRNC OF FL290. AFTER CALLING IN THE DEP TIME AND RETURNING TO THE FREQ, I LOOKED UP AT THE INST PANEL AND SAW THAT THE ACFT WAS ABOUT TO PENETRATE FL290 AND THAT 31000 FT WAS NOW SET IN THE ALT ALERT WINDOW. I ASKED THE PF IF THERE WAS A CHANGE IN OUR ALT CLRNC AND HE INFORMED ME THAT THERE WAS NOT. I IMMEDIATELY DISCONNECTED BOTH THE AUTOPLT AND THE AUTOTHROTTLES. I REDUCED THE PWR AND PUSHED THE NOSE OVER TO HOLD THE ALT AT FL290. WE PENETRATED OUR ALT OF FL290 BY APPROX 600 FT. WHILE I WAS DOING THIS, THE FO ASKED ATC WHAT OUR ASSIGNED ALT WAS. ATC STATED IT AS BEING FL290. THE FO (PF) INFORMED ME THAT HE NEVER PUT 31000 FT IN THE ALT ALERT WINDOW. WE BOTH VERIFIED FL290 WHEN IT WAS INSERTED IN THE ALT ALERT WINDOW. THE ACFT HAD A NUMBER OF ADDITIONAL DFGS MISHAPS DURING THE FLT. THIS SYS CTLS THE AUTOMATION OF THE ACFT. I WOULD ALSO LIKE TO STATE THAT ON PREVIOUS OCCASIONS I HAVE OBSERVED THAT A DIGIT (WHICH IS NOTHING MORE THAN A LIGHT) SET ON THE DFGS PANEL HAS CHANGED TO A HIGHER OR LOWER NUMBER FOR NO APPARENT REASON.
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.