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An EMB145 flight crew overshot its altitude in descent when the flight director fails to indicate an altitude capture. First officer indicated a distraction with WX in local area.
| Attributes | |
| ACN | 407497 |
| Time | |
| Date | 199807 |
| Day | Wed |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : cvg |
| State Reference | OH |
| Altitude | msl bound lower : 6500 msl bound upper : 7000 |
| Environment | |
| Flight Conditions | IMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : cvg |
| Operator | common carrier : air carrier |
| Make Model Name | Embraer Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other |
| Flight Phase | descent : approach descent other |
| Route In Use | arrival other enroute : on vectors |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : commercial pilot : instrument |
| Experience | flight time last 90 days : 170 flight time total : 3500 flight time type : 170 |
| ASRS Report | 407497 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 240 flight time total : 5000 flight time type : 700 |
| ASRS Report | 407510 |
| Events | |
| Anomaly | aircraft equipment problem : less severe altitude deviation : overshoot non adherence : clearance non adherence other |
| Independent Detector | other flight crewa |
| Resolutory Action | controller : issued new clearance |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation other |
Narrative:
Our flight was descending into cincinnati terminal area cleared to descend to 7000 ft. Autoplt was disengaged at approximately 8000 ft. I continued to follow flight commands from flight director. Additionally, captain requested a deviation around WX. I visually scanned for the WX and shortly thereafter heard altitude alerter sound. Altimeter indicated 6500 ft before a climb was initiated. ATC was contacted immediately to confirm assigned altitude. ATC noticed our deviation and reclred flight to 6500 ft and assigned a heading to keep us clear of traffic. No TCASII advisories were observed. During descent flight director did not command a climb even after descending through selected altitude. Callback conversation with reporter revealed the following information: the reporter said that he did not know of any other pilots having this problem but the slowness of the flight director in capturing an altitude selected was known within the company. During training this anomaly of the slow flight director response was brought out to the students, the instructor saying that it was a 'passenger comfort factor' ie, would not pull too many positive G's during leveloff. The reporter claims that this primus 1000 flight director system can be programmed for a faster capture. Reporter said that he would bring this design problem up to his fleet manager for the EMB145 and see if something could be done. He also said that if he hears of future events similar to this he will forward the information to ASRS. Supplemental information from acn 407510: altitude box was set at 7000 ft.
Original NASA ASRS Text
Title: AN EMB145 FLC OVERSHOT ITS ALT IN DSCNT WHEN THE FLT DIRECTOR FAILS TO INDICATE AN ALT CAPTURE. FO INDICATED A DISTR WITH WX IN LCL AREA.
Narrative: OUR FLT WAS DSNDING INTO CINCINNATI TERMINAL AREA CLRED TO DSND TO 7000 FT. AUTOPLT WAS DISENGAGED AT APPROX 8000 FT. I CONTINUED TO FOLLOW FLT COMMANDS FROM FLT DIRECTOR. ADDITIONALLY, CAPT REQUESTED A DEV AROUND WX. I VISUALLY SCANNED FOR THE WX AND SHORTLY THEREAFTER HEARD ALT ALERTER SOUND. ALTIMETER INDICATED 6500 FT BEFORE A CLB WAS INITIATED. ATC WAS CONTACTED IMMEDIATELY TO CONFIRM ASSIGNED ALT. ATC NOTICED OUR DEV AND RECLRED FLT TO 6500 FT AND ASSIGNED A HEADING TO KEEP US CLR OF TFC. NO TCASII ADVISORIES WERE OBSERVED. DURING DSCNT FLT DIRECTOR DID NOT COMMAND A CLB EVEN AFTER DSNDING THROUGH SELECTED ALT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR SAID THAT HE DID NOT KNOW OF ANY OTHER PLTS HAVING THIS PROB BUT THE SLOWNESS OF THE FLT DIRECTOR IN CAPTURING AN ALT SELECTED WAS KNOWN WITHIN THE COMPANY. DURING TRAINING THIS ANOMALY OF THE SLOW FLT DIRECTOR RESPONSE WAS BROUGHT OUT TO THE STUDENTS, THE INSTRUCTOR SAYING THAT IT WAS A 'PAX COMFORT FACTOR' IE, WOULD NOT PULL TOO MANY POSITIVE G'S DURING LEVELOFF. THE RPTR CLAIMS THAT THIS PRIMUS 1000 FLT DIRECTOR SYS CAN BE PROGRAMMED FOR A FASTER CAPTURE. RPTR SAID THAT HE WOULD BRING THIS DESIGN PROB UP TO HIS FLEET MGR FOR THE EMB145 AND SEE IF SOMETHING COULD BE DONE. HE ALSO SAID THAT IF HE HEARS OF FUTURE EVENTS SIMILAR TO THIS HE WILL FORWARD THE INFO TO ASRS. SUPPLEMENTAL INFO FROM ACN 407510: ALT BOX WAS SET AT 7000 FT.
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.