Narrative:

I had planned to fly passenger from slc to sun. While en route, it became clear that sun was below landing minimums, so I diverted to twf. My job was to deliver the aircraft to sun as soon as WX permitted and to leave it in a storage hangar. After about 2 hours had passed, sun was reporting 1800 ft broken ceiling and about 5 mi visibility. I then departed twf VFR, without passenger, for the 55 NM trip up to sun. I flew slightly east for 10 mi, then due north towards wtsox intersection at about 6500 ft. Since the visibility en route was slowly decreasing from about 10 to 5 mi, I set my radar altimeter for a 1000 ft warning and slowed the aircraft to a comfortable 130 KTS. At about 15 NM south of intersection west, the tower reported good visibility and 'few' clouds at 800 ft, with a high overcast above., however, the visibility between me and the airport became less, in a hurry (4 mi, 3 mi), whereas, I had diagnosed the WX as 'haze.' I briefly entered a small cloud. Because of this, I immediately initiated a climb and reversed my course in order to return to twf. Within a 300 ft climb and about 15 seconds, I was in the clear again, yet disappointed with my performance. I did not intend to enter a cloud (IMC) while operating VFR. I called salt lake center, who indicated a long delay for an approach. 90% of my operations are conducted IFR. This particular afternoon, I decided to go VFR, because the flight was supposed to take 14-16 mins, the visibility was portrayed to be VFR, and ZLC normally cannot provide radar services below about 12000 ft. In retrospect, I should realize that the image of clouds and visibility that I 'paint' in my mind by studying reports and forecasts can be inaccurate, even across a short route segment. Also, the fact that haze can hide clouds, especially when visibility is lessened to 3 mi or less, should be appreciated. Afterwards, I learned that conditions at sun had gone from marginal to 1-2 mi visibility in snow, to clear throughout the afternoon. No matter how familiar I am with the plains south of sun, I will prefer to fly only IFR in the future.

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Original NASA ASRS Text

Title: VFR C500 LNDG SUN ENCOUNTERS IMC.

Narrative: I HAD PLANNED TO FLY PAX FROM SLC TO SUN. WHILE ENRTE, IT BECAME CLR THAT SUN WAS BELOW LNDG MINIMUMS, SO I DIVERTED TO TWF. MY JOB WAS TO DELIVER THE ACFT TO SUN AS SOON AS WX PERMITTED AND TO LEAVE IT IN A STORAGE HANGAR. AFTER ABOUT 2 HRS HAD PASSED, SUN WAS RPTING 1800 FT BROKEN CEILING AND ABOUT 5 MI VISIBILITY. I THEN DEPARTED TWF VFR, WITHOUT PAX, FOR THE 55 NM TRIP UP TO SUN. I FLEW SLIGHTLY E FOR 10 MI, THEN DUE N TOWARDS WTSOX INTXN AT ABOUT 6500 FT. SINCE THE VISIBILITY ENRTE WAS SLOWLY DECREASING FROM ABOUT 10 TO 5 MI, I SET MY RADAR ALTIMETER FOR A 1000 FT WARNING AND SLOWED THE ACFT TO A COMFORTABLE 130 KTS. AT ABOUT 15 NM S OF INTXN W, THE TWR RPTED GOOD VISIBILITY AND 'FEW' CLOUDS AT 800 FT, WITH A HIGH OVCST ABOVE., HOWEVER, THE VISIBILITY BTWN ME AND THE ARPT BECAME LESS, IN A HURRY (4 MI, 3 MI), WHEREAS, I HAD DIAGNOSED THE WX AS 'HAZE.' I BRIEFLY ENTERED A SMALL CLOUD. BECAUSE OF THIS, I IMMEDIATELY INITIATED A CLB AND REVERSED MY COURSE IN ORDER TO RETURN TO TWF. WITHIN A 300 FT CLB AND ABOUT 15 SECONDS, I WAS IN THE CLR AGAIN, YET DISAPPOINTED WITH MY PERFORMANCE. I DID NOT INTEND TO ENTER A CLOUD (IMC) WHILE OPERATING VFR. I CALLED SALT LAKE CTR, WHO INDICATED A LONG DELAY FOR AN APCH. 90% OF MY OPS ARE CONDUCTED IFR. THIS PARTICULAR AFTERNOON, I DECIDED TO GO VFR, BECAUSE THE FLT WAS SUPPOSED TO TAKE 14-16 MINS, THE VISIBILITY WAS PORTRAYED TO BE VFR, AND ZLC NORMALLY CANNOT PROVIDE RADAR SVCS BELOW ABOUT 12000 FT. IN RETROSPECT, I SHOULD REALIZE THAT THE IMAGE OF CLOUDS AND VISIBILITY THAT I 'PAINT' IN MY MIND BY STUDYING RPTS AND FORECASTS CAN BE INACCURATE, EVEN ACROSS A SHORT RTE SEGMENT. ALSO, THE FACT THAT HAZE CAN HIDE CLOUDS, ESPECIALLY WHEN VISIBILITY IS LESSENED TO 3 MI OR LESS, SHOULD BE APPRECIATED. AFTERWARDS, I LEARNED THAT CONDITIONS AT SUN HAD GONE FROM MARGINAL TO 1-2 MI VISIBILITY IN SNOW, TO CLR THROUGHOUT THE AFTERNOON. NO MATTER HOW FAMILIAR I AM WITH THE PLAINS S OF SUN, I WILL PREFER TO FLY ONLY IFR IN THE FUTURE.

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.