Narrative:

We had briefed approach to runway 28R and programmed the FMS for runway and approach, along with descent altitudes. Sun was in our eyes. We had the airport initially, but a fog bank began rolling in on the ridges, obscuring the approach end at 5 mi. Bases (clouds) were about 3000 ft otherwise clear. PF was on FMS, PNF set up for navigation #2 localizer and GS. On heading for approach, controller then cleared us to intercept 095 degree radial sfo, for quiet approach and cleared to descend on arrival. PF thought automatic feature of flight director would automatic capture 095 degree radial and fly inbound. However, this, we found out only happens on localizer with 'approach' selected, not 'localizer.' since FMS considered it time to switch from waypoint at 6000 ft to waypoint at 4000 ft. There was no message and descent looked normal, until PNF crosschecked his navigation display while doing checklist. We descended through 6000 ft approximately 3-4 mi early, but visually had the airport. Caught and arrested descent at 4300 ft. ATC cancelled arrival clearance as crossed abeam 4000 ft waypoint requirement. Lesson: use the automation to aid pilot, not waste precious time trying to make automation work, especially near the ground. Cali situation all over again!

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Original NASA ASRS Text

Title: A GULFSTREAM 5 FLT CREW FAILS TO MEET XING RESTR DUE TO IMPROPER USE OF THE AUTOPLT.

Narrative: WE HAD BRIEFED APCH TO RWY 28R AND PROGRAMMED THE FMS FOR RWY AND APCH, ALONG WITH DSCNT ALTS. SUN WAS IN OUR EYES. WE HAD THE ARPT INITIALLY, BUT A FOG BANK BEGAN ROLLING IN ON THE RIDGES, OBSCURING THE APCH END AT 5 MI. BASES (CLOUDS) WERE ABOUT 3000 FT OTHERWISE CLR. PF WAS ON FMS, PNF SET UP FOR NAV #2 LOC AND GS. ON HEADING FOR APCH, CTLR THEN CLRED US TO INTERCEPT 095 DEG RADIAL SFO, FOR QUIET APCH AND CLRED TO DSND ON ARR. PF THOUGHT AUTO FEATURE OF FLT DIRECTOR WOULD AUTO CAPTURE 095 DEG RADIAL AND FLY INBOUND. HOWEVER, THIS, WE FOUND OUT ONLY HAPPENS ON LOC WITH 'APCH' SELECTED, NOT 'LOC.' SINCE FMS CONSIDERED IT TIME TO SWITCH FROM WAYPOINT AT 6000 FT TO WAYPOINT AT 4000 FT. THERE WAS NO MESSAGE AND DSCNT LOOKED NORMAL, UNTIL PNF XCHKED HIS NAV DISPLAY WHILE DOING CHKLIST. WE DSNDED THROUGH 6000 FT APPROX 3-4 MI EARLY, BUT VISUALLY HAD THE ARPT. CAUGHT AND ARRESTED DSCNT AT 4300 FT. ATC CANCELLED ARR CLRNC AS CROSSED ABEAM 4000 FT WAYPOINT REQUIREMENT. LESSON: USE THE AUTOMATION TO AID PLT, NOT WASTE PRECIOUS TIME TRYING TO MAKE AUTOMATION WORK, ESPECIALLY NEAR THE GND. CALI SIT ALL OVER AGAIN!

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.