Narrative:

This incident describes a 'trap' that I found myself in as a result of accommodating a request. No near miss occurred during the flight. During the eaa air show at oshkosh I was asked to ferry the company aircraft from oshkosh to appleton (a strip of about 20 mi). It was hazy with a light rain. I was told the airfield was VFR with about 4 mi visibility. I departed VFR and stayed at 500 AGL as the eaa officials recommended. I was not able to talk to appleton tower until I was 10 mi southwest of appleton due to my low altitude. Appleton tower told me the field was IFR with 800 broken and 2 mi visibility and directed me to call green bay approach. I then flew wbound for about 5-7 mi and I found an area where the visibility was about 4 mi. I could see blue sky above. I climbed to 3500' before I was able to make good contact with green bay. He cleared me to 3000' for a radar vector to the ILS back course. Outside of donne he cleared me for the approach to maintain 2500' until joining the localizer. I had good contact with the ground during the entire flight and I made the mistake of starting to look for the airport when I was about 6 mi out. I became distracted while looking for the airport and descended to 2000' before I was on the localizer. I immediately called approach control and climbed back to 2500'. I completed the approach and landed without any further incident. The lesson to be learned and caution to be given is not to depart on a VFR flight in marginal conditions so as not to be vulnerable to surprises such as this. Fortunately I was able to find an area where I could safely climb high enough to talk to approach control. I am sure the surprise of the situation was a factor in my 500' altitude excursion.

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Original NASA ASRS Text

Title: ALT EXCURSION FROM ASSIGNED WHILE ON LOC BACK COURSE APCH IN IMC CONDITIONS.

Narrative: THIS INCIDENT DESCRIBES A 'TRAP' THAT I FOUND MYSELF IN AS A RESULT OF ACCOMMODATING A REQUEST. NO NEAR MISS OCCURRED DURING THE FLT. DURING THE EAA AIR SHOW AT OSHKOSH I WAS ASKED TO FERRY THE COMPANY ACFT FROM OSHKOSH TO APPLETON (A STRIP OF ABOUT 20 MI). IT WAS HAZY WITH A LIGHT RAIN. I WAS TOLD THE AIRFIELD WAS VFR WITH ABOUT 4 MI VISIBILITY. I DEPARTED VFR AND STAYED AT 500 AGL AS THE EAA OFFICIALS RECOMMENDED. I WAS NOT ABLE TO TALK TO APPLETON TWR UNTIL I WAS 10 MI SW OF APPLETON DUE TO MY LOW ALT. APPLETON TWR TOLD ME THE FIELD WAS IFR WITH 800 BROKEN AND 2 MI VISIBILITY AND DIRECTED ME TO CALL GREEN BAY APCH. I THEN FLEW WBOUND FOR ABOUT 5-7 MI AND I FOUND AN AREA WHERE THE VISIBILITY WAS ABOUT 4 MI. I COULD SEE BLUE SKY ABOVE. I CLIMBED TO 3500' BEFORE I WAS ABLE TO MAKE GOOD CONTACT WITH GREEN BAY. HE CLRED ME TO 3000' FOR A RADAR VECTOR TO THE ILS BACK COURSE. OUTSIDE OF DONNE HE CLRED ME FOR THE APCH TO MAINTAIN 2500' UNTIL JOINING THE LOC. I HAD GOOD CONTACT WITH THE GND DURING THE ENTIRE FLT AND I MADE THE MISTAKE OF STARTING TO LOOK FOR THE ARPT WHEN I WAS ABOUT 6 MI OUT. I BECAME DISTRACTED WHILE LOOKING FOR THE ARPT AND DESCENDED TO 2000' BEFORE I WAS ON THE LOC. I IMMEDIATELY CALLED APCH CTL AND CLIMBED BACK TO 2500'. I COMPLETED THE APCH AND LANDED WITHOUT ANY FURTHER INCIDENT. THE LESSON TO BE LEARNED AND CAUTION TO BE GIVEN IS NOT TO DEPART ON A VFR FLT IN MARGINAL CONDITIONS SO AS NOT TO BE VULNERABLE TO SURPRISES SUCH AS THIS. FORTUNATELY I WAS ABLE TO FIND AN AREA WHERE I COULD SAFELY CLIMB HIGH ENOUGH TO TALK TO APCH CTL. I AM SURE THE SURPRISE OF THE SITUATION WAS A FACTOR IN MY 500' ALT EXCURSION.

Data retrieved from NASA's ASRS site as of August 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.