Narrative:

I was being given vectors to intercept the localizer for the ILS 34 (cu). I was vectored onto the localizer the needle jerked for the localizer a few times and I started following the G/south down unconsciously. The controller told me to turn off of the localizer and to maintain 2000' MSL to receive vectors for another try. I started getting a little stressed and as I turned off of the localizer my altitude deviated down to about 1600-1700' MSL. Realizing what was happening, I calmed down, started fixing my heading and altitude and remained calm the rest of the flight. I successfully shot the ILS 34 (cll) on the second try with no problem. In my opinion there were several decisions and factors that allowed me to get into that situation. First of all the WX was forecast as 2300 broken 5-7 mi visibility not 400 obscured 1 1/2 mi visibility. I did not mentally prepare for an approach that low. Second of all I had 4/5 hours of actual. That day I spent 5.3 hours in the clouds. The WX forecast would have put me on top of the clouds, but instead I spent the whole flight on the way back in the clouds with twice the expected headwinds. This left me with just enough fuel to make it to my alternate, which I hadn't filed because I didn't need one when I took off, after shooting the approachs. The combination of fuel concerns, low WX and low time made me very jittery and led to my altitude and heading deviations.

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Original NASA ASRS Text

Title: GA SMA TRACK HEADING DEVIATION AND ALT DEVIATION EXCURSION FROM CLRNC ALT WHILE ON RADAR VECTORS FOR IAP ILS APCH.

Narrative: I WAS BEING GIVEN VECTORS TO INTERCEPT THE LOC FOR THE ILS 34 (CU). I WAS VECTORED ONTO THE LOC THE NEEDLE JERKED FOR THE LOC A FEW TIMES AND I STARTED FOLLOWING THE G/S DOWN UNCONSCIOUSLY. THE CTLR TOLD ME TO TURN OFF OF THE LOC AND TO MAINTAIN 2000' MSL TO RECEIVE VECTORS FOR ANOTHER TRY. I STARTED GETTING A LITTLE STRESSED AND AS I TURNED OFF OF THE LOC MY ALT DEVIATED DOWN TO ABOUT 1600-1700' MSL. REALIZING WHAT WAS HAPPENING, I CALMED DOWN, STARTED FIXING MY HDG AND ALT AND REMAINED CALM THE REST OF THE FLT. I SUCCESSFULLY SHOT THE ILS 34 (CLL) ON THE SEC TRY WITH NO PROB. IN MY OPINION THERE WERE SEVERAL DECISIONS AND FACTORS THAT ALLOWED ME TO GET INTO THAT SITUATION. FIRST OF ALL THE WX WAS FORECAST AS 2300 BROKEN 5-7 MI VISIBILITY NOT 400 OBSCURED 1 1/2 MI VISIBILITY. I DID NOT MENTALLY PREPARE FOR AN APCH THAT LOW. SEC OF ALL I HAD 4/5 HRS OF ACTUAL. THAT DAY I SPENT 5.3 HRS IN THE CLOUDS. THE WX FORECAST WOULD HAVE PUT ME ON TOP OF THE CLOUDS, BUT INSTEAD I SPENT THE WHOLE FLT ON THE WAY BACK IN THE CLOUDS WITH TWICE THE EXPECTED HEADWINDS. THIS L ME WITH JUST ENOUGH FUEL TO MAKE IT TO MY ALTERNATE, WHICH I HADN'T FILED BECAUSE I DIDN'T NEED ONE WHEN I TOOK OFF, AFTER SHOOTING THE APCHS. THE COMBINATION OF FUEL CONCERNS, LOW WX AND LOW TIME MADE ME VERY JITTERY AND LED TO MY ALT AND HDG DEVS.

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.