A C172 pilot found himself IMC in VFR.

Attributes
ACN	537273
Time
Date	200202
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : ll10.airport
State Reference	IL
Altitude	msl single value : 1400
Environment
Flight Conditions	IMC
Weather Elements	Fog
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : c90.tracon tower : dpa.tower tower : arr.tower
Operator	general aviation : personal
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Route In Use	approach : visual
Flight Plan	None
Person 1
Affiliation	other
Function	flight crew : single pilot
Experience	flight time last 90 days : 18 flight time total : 150 flight time type : 150
ASRS Report	537273
Person 2
Affiliation	government : faa
Function	controller : local
Events
Anomaly	inflight encounter : weather inflight encounter : vfr in imc inflight encounter other non adherence : far non adherence : published procedure
Independent Detector	other flight crewa
Resolutory Action	controller : provided flight assist controller : issued new clearance flight crew : diverted to another airport
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Weather Flight Crew Human Performance Airspace Structure
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On descent and approach, I discovered a layer of low fog had completely covered LL10. I briefly entered the fog layer then executed the missed approach procedure. Monitored karr ATIS once again and then established radio contact with karr tower. Advised situation. Informed only IFR apchsecond officerps were being accepted. Instructed to contact ord approach. I established contact with ord approach. Approach assigned me a transponder code and instructed me to stand by. While maintaining required cloud clearance and standing by, I noticed dpa airport was visible. Monitored dpa ATIS and contacted tower. ATIS stated IFR approachs only and tower would not accept a visual approach. I requested an SVFR. The SVFR was granted. I was cleared to enter the airspace and cleared for runway 2L. Landed without incident. This incident was caused by the rapid and unexpected closure of ground fog. This incident could have been prevented by a closer monitoring of the temperature/dewpoint spread and by contacting flight watch for the nearest VFR airport.

Original NASA ASRS Text

Title: A C172 PLT FOUND HIMSELF IMC IN VFR.

Narrative: ON DSCNT AND APCH, I DISCOVERED A LAYER OF LOW FOG HAD COMPLETELY COVERED LL10. I BRIEFLY ENTERED THE FOG LAYER THEN EXECUTED THE MISSED APCH PROC. MONITORED KARR ATIS ONCE AGAIN AND THEN ESTABLISHED RADIO CONTACT WITH KARR TWR. ADVISED SIT. INFORMED ONLY IFR APCHS/OPS WERE BEING ACCEPTED. INSTRUCTED TO CONTACT ORD APCH. I ESTABLISHED CONTACT WITH ORD APCH. APCH ASSIGNED ME A XPONDER CODE AND INSTRUCTED ME TO STAND BY. WHILE MAINTAINING REQUIRED CLOUD CLRNC AND STANDING BY, I NOTICED DPA ARPT WAS VISIBLE. MONITORED DPA ATIS AND CONTACTED TWR. ATIS STATED IFR APCHS ONLY AND TWR WOULD NOT ACCEPT A VISUAL APCH. I REQUESTED AN SVFR. THE SVFR WAS GRANTED. I WAS CLRED TO ENTER THE AIRSPACE AND CLRED FOR RWY 2L. LANDED WITHOUT INCIDENT. THIS INCIDENT WAS CAUSED BY THE RAPID AND UNEXPECTED CLOSURE OF GND FOG. THIS INCIDENT COULD HAVE BEEN PREVENTED BY A CLOSER MONITORING OF THE TEMP/DEWPOINT SPREAD AND BY CONTACTING FLT WATCH FOR THE NEAREST VFR ARPT.

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.