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.