PA44 FLC TOOK EVASIVE ACTION TURNS DSCNT TO AVOID A C310; NOT UNDER DAB TRACON CTL. CTLR ISSUED A TFC ALERT IMMEDIATE TURN WHEN THE UNIDENTED TARGET WAS OBSERVED IN THE IMMEDIATE VICINITY OF THE PA44.

Narrative

WE WERE ON AN IFR FLT PLAN FROM CHARLESTON; SC; TO TITUSVILLE; FL. WHILE FLYING OUR ASSIGNED ALT OF 4000 FT ON V3; DAB APCH SAID 'AZTEC XXX; IF YOU DON'T HAVE THE TFC IN SIGHT; MAKE AN IMMEDIATE L TURN.' I STARTED A L TURN AND CONFIRMED THE CALL WAS FOR SEMINOLE YYY. AT THIS POINT; WE WERE POPPING IN AND OUT OF CLOUDS WITH VERY LITTLE CONTACT WITH THE GND. DEFINITE IMC CONDITIONS. ABOUT A SECOND LATER; THE OTHER ACFT APPEARED NO MORE THAN 100 FT IN FRONT OF US AS IT POPPED OUT OF A CLOUD. THE OTHER PLT AND I BOTH INSTINCTIVELY GRABBED THE CTLS AND PUSHED HARD L AND DOWN. IT PASSED NO MORE THAN 50 FT ABOVE US SLIGHTLY TO OUR R. I ASKED APCH FOR HIS TAIL NUMBERS; BUT IT TURNS OUT HE WAS VFR. WE WERE SKIRTING THE UPPER END OF DAB'S CLASS C; SO I ASSUME THE OTHER ACFT SIMPLY WANTED TO AVOID TALKING TO THEM; HENCE CLBING SLIGHTLY ABOVE. APCH APOLOGIZED FOR THE LATE CALL; SAYING THAT THE OTHER PLANE WAS NOT A SECONDARY TARGET TILL THE LAST MIN; OR THAT HE WASN'T PICKING UP HIS MODE C UNTIL THE LAST MIN. THE DECISION OF THE OTHER PLANE TO CLB INTO IMC TO AVOID RADIO COM WAS FOOLISH AND ALMOST GOT BOTH OF US KILLED. WE OBSERVED THE OTHER ACFT; A LIGHT TWIN; WAS WHITE WITH GREEN AND GOLD STRIPES. SUPPLEMENTAL INFO FROM ACN 392520: AT THE SAME TIME WE CAME THROUGH A CLOUD; CHKED FOR TFC; THE OTHER ACFT CAME OUT OF A CLOUD; WE PUSHED DOWN AND BANKED GREATER THAN 30 DEGS TO MISS TFC. APCH ADVISED US THAT THE TARGET JUST RECENTLY APPEARED ON HIS SCOPE; AND HAD NO INFO ABOUT THAT ACFT.