Narrative:

After arriving at smf several hours late due to WX delays at departure point, we were given vectors to runway 16 ILS. WX was about 2000-3000 ft ceilings, 5 mi visibility with rain showers and gusty surface winds. Expecting a rather simple approach, we descended out of altitude and entered clouds at about 10000 ft. Approach advised us that there were some reports of turbulence on final by other aircraft earlier that evening. We had WX radar on and it showed only rain showers and no thunderstorms. We were first cleared down to 3000 ft, then 1800 ft, and cleared for the approach. Out of 3500 ft we encountered moderate turbulence that made the aircraft difficult to control. We leveled at 1800 ft and got turbulence that was even worse. The PF became distracted and flew through the localizer on intercept heading despite calls from myself indicating the same. Approach revectored us onto the ILS from other side during which we had altitude excursions of minus 200 to plus 1000 ft of assigned altitude due to turbulence and distraction of the PF by these unforeseen elements. The end result was a very unstabilized close-in intercept and approach that ended safely but was quite frightening. I must stress that we were all very tired (we were on east coast time and had been up an average of 18-21 hours) and unprepared mentally for what we encountered. Supplemental information from acn 234607: I was maintaining attitude and was not terribly concerned about altitude. I was more concerned with not over stressing the airplane. I am familiar with the local topography and was not concerned about ground contact. During this approach nearly all of the GPWS warnings sounded: GS, sink rate, pull up, plus a stall warning at 210 IAS. The airspeed deviated as much as 30 KIAS.

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Original NASA ASRS Text

Title: DUE TO MODERATE, APCHING SEVERE TURB, LGT HAS ALTDEVS AND FLIES THROUGH LOC COURSE.

Narrative: AFTER ARRIVING AT SMF SEVERAL HRS LATE DUE TO WX DELAYS AT DEP POINT, WE WERE GIVEN VECTORS TO RWY 16 ILS. WX WAS ABOUT 2000-3000 FT CEILINGS, 5 MI VISIBILITY WITH RAIN SHOWERS AND GUSTY SURFACE WINDS. EXPECTING A RATHER SIMPLE APCH, WE DSNDED OUT OF ALT AND ENTERED CLOUDS AT ABOUT 10000 FT. APCH ADVISED US THAT THERE WERE SOME RPTS OF TURB ON FINAL BY OTHER ACFT EARLIER THAT EVENING. WE HAD WX RADAR ON AND IT SHOWED ONLY RAIN SHOWERS AND NO TSTMS. WE WERE FIRST CLRED DOWN TO 3000 FT, THEN 1800 FT, AND CLRED FOR THE APCH. OUT OF 3500 FT WE ENCOUNTERED MODERATE TURB THAT MADE THE ACFT DIFFICULT TO CTL. WE LEVELED AT 1800 FT AND GOT TURB THAT WAS EVEN WORSE. THE PF BECAME DISTRACTED AND FLEW THROUGH THE LOC ON INTERCEPT HDG DESPITE CALLS FROM MYSELF INDICATING THE SAME. APCH REVECTORED US ONTO THE ILS FROM OTHER SIDE DURING WHICH WE HAD ALT EXCURSIONS OF MINUS 200 TO PLUS 1000 FT OF ASSIGNED ALT DUE TO TURB AND DISTR OF THE PF BY THESE UNFORESEEN ELEMENTS. THE END RESULT WAS A VERY UNSTABILIZED CLOSE-IN INTERCEPT AND APCH THAT ENDED SAFELY BUT WAS QUITE FRIGHTENING. I MUST STRESS THAT WE WERE ALL VERY TIRED (WE WERE ON E COAST TIME AND HAD BEEN UP AN AVERAGE OF 18-21 HRS) AND UNPREPARED MENTALLY FOR WHAT WE ENCOUNTERED. SUPPLEMENTAL INFO FROM ACN 234607: I WAS MAINTAINING ATTITUDE AND WAS NOT TERRIBLY CONCERNED ABOUT ALT. I WAS MORE CONCERNED WITH NOT OVER STRESSING THE AIRPLANE. I AM FAMILIAR WITH THE LCL TOPOGRAPHY AND WAS NOT CONCERNED ABOUT GND CONTACT. DURING THIS APCH NEARLY ALL OF THE GPWS WARNINGS SOUNDED: GS, SINK RATE, PULL UP, PLUS A STALL WARNING AT 210 IAS. THE AIRSPD DEVIATED AS MUCH AS 30 KIAS.

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.