C208 PLT AND A MOONEY HAD AN NMAC AT BWG.

Narrative

INDIVIDUAL WAS LOST/DISORIENTED DESPITE SUBSTANTIAL ASSISTANCE FROM OTHER ACFT APCHING BWG AS WELL AS ZME PROVIDING VFR RADAR ADVISORIES. INDIVIDUAL MADE MULTIPLE CLBS AND DSCNTS ONCE VISUAL CONTACT WAS ESTABLISHED WITH THE AIRFIELD. PLT MIGRATED W OF THE FIELD AND CLBED TO AN ALT OF 3500 FT MSL (PER CTAF BROADCAST) AND WAS HEADING TOWARD THE NW. AS I ARRIVED FROM THE W; ABOUT 6 NM W OF BWG; I MADE VISUAL CONTACT WITH THE MOONEY AND COULD CONFIRM HIS POS AND ALT. I BEGAN A DSCNT BELOW HIS ALT AND HEADED 2-3 MI S OF HIS CURRENT POS AND AWAY FROM HIS APPARENT VECTOR. PASSING THROUGH HIS ALT; I NOTICED HE BEGAN A DSNDING L TURN. AS I GOT CLOSER; I COULD SEE HIS CTL OF THE ACFT BECAME MORE ERRATIC AS IT APPEARED HE MAY HAVE HAD ME IN SIGHT. I HAD MADE MULTIPLE ANNOUNCEMENTS ON THE CTAF REGARDING MY POS; ALT AND DIRECTION OF FLT AND NEVER RECEIVED AN ACKNOWLEDGEMENT OR INTERROGATION FROM THE MOONEY. HE APPEARED TO BE MORE FOCUSED ON THE ARPT THAN THE TFC ARRIVING AROUND HIM AND CARELESSLY BEGAN A TURN AND DSCNT TO THE W AND DIRECTLY INTO MY APCHING PATH. 2 MORE ATTEMPTS TO QUERY HIS INTENTIONS AND VERIFY VISUAL CONTACT WITH ME WERE UNACKNOWLEDGED. HE CONTINUED HIS TURN AND DSCNT INTO MY PATH AS I TOOK EVASIVE ACTION WITH A VERY STEEP DSCNT STRAIGHT AHEAD TO PASS UNDERNEATH THE MOONEY. I LOST VISUAL SIGHT OF THE MOONEY AS I PASSED UNDERNEATH AND IN FRONT OF HIM. I ESTIMATE OUR SEPARATION TO BE LESS THAN 100 FT LATERALLY AND UNDER 200 FT VERTLY. IT WAS CLOSE ENOUGH TO DISTINGUISH PIANO HINGES ON THE MAIN LNDG GEAR DOORS. AN ATTEMPT TO DEBRIEF THE MOONEY PLT ONCE ON THE GND WENT LARGELY UNEMPHATIC AND PASSIVELY RESPONDENT TO THE IMPACT OF MY INTENTIONS TO FILE AN NMAC RPT WITH ZME. HIS DEMEANOR; STATEMENTS MADE; APPEARANCE AND CREDENTIALS CAUSED CONSIDERABLE QUESTION AND CONCERN. THESE DETAILS HAVE BEEN PASSED ONTO THE FAA AND TSA.