A FORMATION OF 3 SMA'S HAS AN NMAC WITH AN LTT NEAR CLOUDS.

Narrative

ON AN IFR FLT PLAN FROM BRISTOL; TN (TRI) TO DYERSBURG; TN; WE (FLT OF 3 PITTS SPECIALS CERTIFIED FOR IFR FLT) REACHED CLR CONDITIONS ABOVE A SCATTERED LAYER. AT 8000 FT MSL; PASSING THE KNOXVILLE ARSA WBOUND; I CANCELLED IFR IN AN EFFORT TO ALLEVIATE THE WORKLOAD FOR MY WINGMEN. CLR CONDITIONS HAD BEEN RPTED BY AWOS IN THE DYERSBURG AREA. AFTER CANCELLING IFR; THE FLT DSNDED AND CRUISED AT 6500 FT MSL WITH GOOD VFR CLOUD SEPARATION (OVER 1000 FT). BUILD-UPS FROM THE SCATTERED LAYER IN THE AREA OF NASHVILLE; TN; CAUSED US TO MAKE MINOR DEVS TO RETAIN ADEQUATE VFR COULD SEPARATION. PASSING NASHVILLE; THE HT OF THE SCATTERED LAYER BEGAN INCREASING; CAUSING THE FLT TO CLB SLIGHTLY TO RETAIN VFR CLOUD SEPARATION CRITERIA. WITH BUILD-UPS ABOVE OUR ALT AT 12 O'CLOCK AND APPROX 3 MI; I MADE THE DECISION TO DSND VFR THROUGH THE SCATTERED LAYER TO 4500 FT MSL AND RESUME CRUISE. WITHIN LESS THAN 10 SECONDS OF THAT DECISION A TWIN TURBOPROP COMMUTER ACFT APPEARED AT 12 O'CLOCK; SLIGHTLY HIGH OUT OF THE BUILD-UP AHEAD OF US. BECAUSE MY DSCNT HAD JUST BEGUN; NO FURTHER CORRECTIVE ACTION WAS NECESSARY ON MY PART. FROM THE TIME OF IFR CANCELLATION MY L WINGMAN HAD BEEN SQUAWKING 1200 WITH MODE C FOR THE FLT OF 3. HIS ACFT WAS THE CLOSEST ACFT OF THE FLT TO THE OPPOSITE DIRECTION TFC. IT APPEARS THAT STANDARD FLT SEPARATION MINIMUMS (FOR IFR AND VFR TFC) WERE EXCEEDED RESULTING IN THE NEAR MISS SIT.