Narrative:

I departed ffo to do a local training flight to the south and west. The WX on takeoff was 6 mi visibility in haze, a few clouds at 3000 ft. I first flew to mgy airport to do a touch and go on runway 02, there was haze from ground level to about 3000 ft MSL, but I had little difficulty seeing. I then flew to green county (I19) to do crosswind practice on runway 7. The wind was 330 degrees at about 11 KTS. After the third landing, I departed runway 7, climbed to 3000 ft, and turned left to find point alpha (about 120 degree radial for 5 NM off the ffo VOR), the VFR entry point to the patterson class D for aeronautical club aircraft. To that point in time, the WX remained the same as when I had departed patterson (hazy up to about 3000 ft MSL). As I leveled at 3000 ft, about 3-4 mi southwest of point alpha, the clouds closed under me, and started closing around me. I could see clearly above, but I was worried about getting caught on top, so I descended to 2000 ft through what looked like hazy holes in the clouds. As I leveled at 2000 ft, the visibility dropped to almost zero. Instead of descending into the haze I expected, I descended into IMC. At that point, I had the choice of returning to I19, trying to fly on south or east out of IMC, climbing out of IMC, or continuing on to patterson. I wasn't sure if the WX had closed behind me, and I didn't know if I could find I19. I didn't want to climb to find clear air yet, as I would have to come down sometime. So, I called patterson tower, explained where I was (in a left 360 degrees about a mi outside of class D near point alpha) and asked for help finding patterson. Tower gave me a 340 degree heading and told me the ceiling was about 700 ft AGL over the field. I slowly descended from 1800 ft MSL to 1500 ft MSL, still in IMC, and talked to tower until I saw the approach end of runway 23R directly below me. I was at about 500 ft AGL. I turned to land long on runway 23R. I was in IMC for about 5 mins. During my time in IMC I had the pitot heat on and paid particular attention to the engine 'song,' ready to use carburetor heat if necessary. After I landed, tower told me the change from haze to overcast caught them by surprise, apparently there was a sudden temperature drop that caused the clouds to form. Throughout the flight, winds remained at 330 degrees 9 KTS to 330 degrees 11 KTS. Throughout the flight, the WX remained the same, until after my departure from I19 heading back to ffo. I had no indication even during my takeoff roll at I19 that the WX was closing in. There was no data to predict that I would encounter IMC conditions, and the haze turned to overcast around me very suddenly. I elected to continue into the IMC, since I was only 6 mi from ffo and had control of the aircraft and contact with the tower, who had radar contact with me. I had no confidence that I would fly out of the IMC if I had turned around to try to find I19, or one of the other small airports to the south. I thought it safer to fly to a large runway that I knew I had help to find, would be lighted, and would provide plenty of room to land on in the crosswind conditions I had. My hood training paid off, in that I was in control of the aircraft at all times. In this case, I don't think I could have prevented my entry into IMC, since I had no information to tell me to stay on the ground rather than return to ffo. Since I also had no idea which way would lead out of the IMC, the election to continue to ffo under control was the correct one for me at the time.

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Original NASA ASRS Text

Title: PA28-161 PLT ENCOUNTERS ABRUPT WX CHANGE ON RETURN TO HOME BASE AND ENDS UP IN IMC. ATIS WAS STILL ISSUING THE PREVIOUS WX WHICH WAS HAZE TO 3000 FT. CONTACTING TWR HE RECEIVES VECTORS TO THE ARPT.

Narrative: I DEPARTED FFO TO DO A LCL TRAINING FLT TO THE S AND W. THE WX ON TKOF WAS 6 MI VISIBILITY IN HAZE, A FEW CLOUDS AT 3000 FT. I FIRST FLEW TO MGY ARPT TO DO A TOUCH AND GO ON RWY 02, THERE WAS HAZE FROM GND LEVEL TO ABOUT 3000 FT MSL, BUT I HAD LITTLE DIFFICULTY SEEING. I THEN FLEW TO GREEN COUNTY (I19) TO DO XWIND PRACTICE ON RWY 7. THE WIND WAS 330 DEGS AT ABOUT 11 KTS. AFTER THE THIRD LNDG, I DEPARTED RWY 7, CLBED TO 3000 FT, AND TURNED L TO FIND POINT ALPHA (ABOUT 120 DEG RADIAL FOR 5 NM OFF THE FFO VOR), THE VFR ENTRY POINT TO THE PATTERSON CLASS D FOR AERO CLUB ACFT. TO THAT POINT IN TIME, THE WX REMAINED THE SAME AS WHEN I HAD DEPARTED PATTERSON (HAZY UP TO ABOUT 3000 FT MSL). AS I LEVELED AT 3000 FT, ABOUT 3-4 MI SW OF POINT ALPHA, THE CLOUDS CLOSED UNDER ME, AND STARTED CLOSING AROUND ME. I COULD SEE CLEARLY ABOVE, BUT I WAS WORRIED ABOUT GETTING CAUGHT ON TOP, SO I DSNDED TO 2000 FT THROUGH WHAT LOOKED LIKE HAZY HOLES IN THE CLOUDS. AS I LEVELED AT 2000 FT, THE VISIBILITY DROPPED TO ALMOST ZERO. INSTEAD OF DSNDING INTO THE HAZE I EXPECTED, I DSNDED INTO IMC. AT THAT POINT, I HAD THE CHOICE OF RETURNING TO I19, TRYING TO FLY ON S OR E OUT OF IMC, CLBING OUT OF IMC, OR CONTINUING ON TO PATTERSON. I WASN'T SURE IF THE WX HAD CLOSED BEHIND ME, AND I DIDN'T KNOW IF I COULD FIND I19. I DIDN'T WANT TO CLB TO FIND CLR AIR YET, AS I WOULD HAVE TO COME DOWN SOMETIME. SO, I CALLED PATTERSON TWR, EXPLAINED WHERE I WAS (IN A L 360 DEGS ABOUT A MI OUTSIDE OF CLASS D NEAR POINT ALPHA) AND ASKED FOR HELP FINDING PATTERSON. TWR GAVE ME A 340 DEG HDG AND TOLD ME THE CEILING WAS ABOUT 700 FT AGL OVER THE FIELD. I SLOWLY DSNDED FROM 1800 FT MSL TO 1500 FT MSL, STILL IN IMC, AND TALKED TO TWR UNTIL I SAW THE APCH END OF RWY 23R DIRECTLY BELOW ME. I WAS AT ABOUT 500 FT AGL. I TURNED TO LAND LONG ON RWY 23R. I WAS IN IMC FOR ABOUT 5 MINS. DURING MY TIME IN IMC I HAD THE PITOT HEAT ON AND PAID PARTICULAR ATTN TO THE ENG 'SONG,' READY TO USE CARB HEAT IF NECESSARY. AFTER I LANDED, TWR TOLD ME THE CHANGE FROM HAZE TO OVCST CAUGHT THEM BY SURPRISE, APPARENTLY THERE WAS A SUDDEN TEMP DROP THAT CAUSED THE CLOUDS TO FORM. THROUGHOUT THE FLT, WINDS REMAINED AT 330 DEGS 9 KTS TO 330 DEGS 11 KTS. THROUGHOUT THE FLT, THE WX REMAINED THE SAME, UNTIL AFTER MY DEP FROM I19 HEADING BACK TO FFO. I HAD NO INDICATION EVEN DURING MY TKOF ROLL AT I19 THAT THE WX WAS CLOSING IN. THERE WAS NO DATA TO PREDICT THAT I WOULD ENCOUNTER IMC CONDITIONS, AND THE HAZE TURNED TO OVCST AROUND ME VERY SUDDENLY. I ELECTED TO CONTINUE INTO THE IMC, SINCE I WAS ONLY 6 MI FROM FFO AND HAD CTL OF THE ACFT AND CONTACT WITH THE TWR, WHO HAD RADAR CONTACT WITH ME. I HAD NO CONFIDENCE THAT I WOULD FLY OUT OF THE IMC IF I HAD TURNED AROUND TO TRY TO FIND I19, OR ONE OF THE OTHER SMALL ARPTS TO THE S. I THOUGHT IT SAFER TO FLY TO A LARGE RWY THAT I KNEW I HAD HELP TO FIND, WOULD BE LIGHTED, AND WOULD PROVIDE PLENTY OF ROOM TO LAND ON IN THE XWIND CONDITIONS I HAD. MY HOOD TRAINING PAID OFF, IN THAT I WAS IN CTL OF THE ACFT AT ALL TIMES. IN THIS CASE, I DON'T THINK I COULD HAVE PREVENTED MY ENTRY INTO IMC, SINCE I HAD NO INFO TO TELL ME TO STAY ON THE GND RATHER THAN RETURN TO FFO. SINCE I ALSO HAD NO IDEA WHICH WAY WOULD LEAD OUT OF THE IMC, THE ELECTION TO CONTINUE TO FFO UNDER CTL WAS THE CORRECT ONE FOR ME AT THE TIME.

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.