Narrative:

Proceeding from ft lauderdale to marathon, fl, on an IFR flight plan and in IFR conditions. The ZMA had cleared flight to proceed direct the marathon radio beacon (260 NM) and after clearing reported northbound traffic. Clearance was received to descend to 2000' from 4000'. The northbound traffic was not seen by flight due to IFR conditions. A descent was begun and while on heading 225 degrees, at 2300' and approximately 25 NM from mth, my first officer called for an immediate level off, as were about to descend on top of a light single engine airplane. The descent was halted and the aircraft passed close by and below our right wing. My first officer noted the last #'south as we passed by. The descent was continued and we broke out of the clouds at 15 NM from mth, but remained in light rain. Mth was idented visually and an approach and landing accomplished. While at the terminal we watched a single engine aircraft land and recognized this as the one we had almost hit. We could not read the 3' #'south as he taxied past, so we drove to the FBO where he parked. We spoke briefly to the pilot asking if he saw us pass him. He said yes. He responded that he was the pilot he responded (when asked of fly into IFR WX) west/O a clearance that the WX was not as predicted. He was evasive and did not give his name. I do not believe he was on an IFR flight plan nor was he in communication with center. The incident was initially reported to center in-flight by asking if they held this contact. They said no. We passed the near miss to them. FAA miami called me and I reported the situation to him. The incident reflects the dangerous, illegal (and nearly disastrous) situation when aircraft are intentionally flown into IFR conditions west/O clearance.

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Original NASA ASRS Text

Title: CLOSE PROX COMMUTER-SMT GA-SMA FLYING VFR IN IMC.

Narrative: PROCEEDING FROM FT LAUDERDALE TO MARATHON, FL, ON AN IFR FLT PLAN AND IN IFR CONDITIONS. THE ZMA HAD CLRED FLT TO PROCEED DIRECT THE MARATHON RADIO BEACON (260 NM) AND AFTER CLRING RPTED NBOUND TFC. CLRNC WAS RECEIVED TO DSND TO 2000' FROM 4000'. THE NBOUND TFC WAS NOT SEEN BY FLT DUE TO IFR CONDITIONS. A DSCNT WAS BEGUN AND WHILE ON HDG 225 DEGS, AT 2300' AND APPROX 25 NM FROM MTH, MY F/O CALLED FOR AN IMMEDIATE LEVEL OFF, AS WERE ABOUT TO DSND ON TOP OF A LIGHT SINGLE ENG AIRPLANE. THE DSCNT WAS HALTED AND THE ACFT PASSED CLOSE BY AND BELOW OUR RIGHT WING. MY F/O NOTED THE LAST #'S AS WE PASSED BY. THE DSCNT WAS CONTINUED AND WE BROKE OUT OF THE CLOUDS AT 15 NM FROM MTH, BUT REMAINED IN LIGHT RAIN. MTH WAS IDENTED VISUALLY AND AN APCH AND LNDG ACCOMPLISHED. WHILE AT THE TERMINAL WE WATCHED A SINGLE ENG ACFT LAND AND RECOGNIZED THIS AS THE ONE WE HAD ALMOST HIT. WE COULD NOT READ THE 3' #'S AS HE TAXIED PAST, SO WE DROVE TO THE FBO WHERE HE PARKED. WE SPOKE BRIEFLY TO THE PLT ASKING IF HE SAW US PASS HIM. HE SAID YES. HE RESPONDED THAT HE WAS THE PLT HE RESPONDED (WHEN ASKED OF FLY INTO IFR WX) W/O A CLRNC THAT THE WX WAS NOT AS PREDICTED. HE WAS EVASIVE AND DID NOT GIVE HIS NAME. I DO NOT BELIEVE HE WAS ON AN IFR FLT PLAN NOR WAS HE IN COM WITH CENTER. THE INCIDENT WAS INITIALLY RPTED TO CENTER INFLT BY ASKING IF THEY HELD THIS CONTACT. THEY SAID NO. WE PASSED THE NEAR MISS TO THEM. FAA MIAMI CALLED ME AND I RPTED THE SITUATION TO HIM. THE INCIDENT REFLECTS THE DANGEROUS, ILLEGAL (AND NEARLY DISASTROUS) SITUATION WHEN ACFT ARE INTENTIONALLY FLOWN INTO IFR CONDITIONS W/O CLRNC.

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.