Descended early on ILS approach. Controller caught and aircraft executed missed approach.

Attributes
ACN	168136
Time
Date	199101
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : pdk
State Reference	GA
Altitude	msl bound lower : 2200 msl bound upper : 3100
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : atl tower : lax
Operator	general aviation : personal
Make Model Name	Small Aircraft, High Wing, 1 Eng, Retractable Gear
Flight Phase	descent : approach landing : go around
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private pilot : instrument
Experience	flight time last 90 days : 62 flight time total : 462
ASRS Report	168136
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : published procedure
Independent Detector	other controllera
Resolutory Action	other other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I departed amg IFR for pdk. I was vectored for the ILS 20L to pdk. After establishing myself on the localizer, I saw the G/south coming in and so I started descending. The G/south indicator stayed fixed in the center and it appears as if the flag was hidden. I did not receive the OM and so I looked at the flag again and with the INS lighting it still appeared to be hidden. I reduced my descent and the G/south stayed fixed level west/O moving. I stopped my descent at around 2200' and called the controller to see if I was on the G/south. He requested my altitude. I told him, and he told me to return to 3000'. I executed a missed approach. I believe 2 factors played a part in this potentially dangerous altitude deviation. 1) the poor lighting on the INS panel of this small aircraft, and 2) that I should have realized that I was not at the OM because the controller had not handed me off to the tower. This was also the first time I had flown an INS approach at night in difficult WX conditions. I flew from pdk to fty 30 mins later in extreme turbulence and flew the ILS 8 west/O incident.

Original NASA ASRS Text

Title: DESCENDED EARLY ON ILS APCH. CTLR CAUGHT AND ACFT EXECUTED MISSED APCH.

Narrative: I DEPARTED AMG IFR FOR PDK. I WAS VECTORED FOR THE ILS 20L TO PDK. AFTER ESTABLISHING MYSELF ON THE LOC, I SAW THE G/S COMING IN AND SO I STARTED DSNDING. THE G/S INDICATOR STAYED FIXED IN THE CENTER AND IT APPEARS AS IF THE FLAG WAS HIDDEN. I DID NOT RECEIVE THE OM AND SO I LOOKED AT THE FLAG AGAIN AND WITH THE INS LIGHTING IT STILL APPEARED TO BE HIDDEN. I REDUCED MY DSNT AND THE G/S STAYED FIXED LEVEL W/O MOVING. I STOPPED MY DSNT AT AROUND 2200' AND CALLED THE CTLR TO SEE IF I WAS ON THE G/S. HE REQUESTED MY ALT. I TOLD HIM, AND HE TOLD ME TO RETURN TO 3000'. I EXECUTED A MISSED APCH. I BELIEVE 2 FACTORS PLAYED A PART IN THIS POTENTIALLY DANGEROUS ALT DEVIATION. 1) THE POOR LIGHTING ON THE INS PANEL OF THIS SMA, AND 2) THAT I SHOULD HAVE REALIZED THAT I WAS NOT AT THE OM BECAUSE THE CTLR HAD NOT HANDED ME OFF TO THE TWR. THIS WAS ALSO THE FIRST TIME I HAD FLOWN AN INS APCH AT NIGHT IN DIFFICULT WX CONDITIONS. I FLEW FROM PDK TO FTY 30 MINS LATER IN EXTREME TURB AND FLEW THE ILS 8 W/O INCIDENT.

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.