Narrative:

Just south of brentwood I was given a left turn, and a few mi ese of the wsm radio tower was advised to 'use own navigation'. I turned right to 120 degrees so as to eventually intercept the 133 bna right, remaining at 3000' and under the control of nashville departure. At approximately xa:40 local time the departure controller called '...traffic 12 O'clock, 2 mi, heading southwest, type and altitude unknown'. I replied, 'looking'. I saw no traffic, however, and continued looking. Perhaps a min later, I observed a high wing single engine aircraft, white with dark trim, pass directly beneath me, heading southwest, and I believe, descending. I advised departure, and upon query stated the distance below me was maybe 500'. In retrospect, I feel the sep was a good bit less.

Google
 

Original NASA ASRS Text

Title: TWO SMAS HAVE NMAC.

Narrative: JUST S OF BRENTWOOD I WAS GIVEN A L TURN, AND A FEW MI ESE OF THE WSM RADIO TWR WAS ADVISED TO 'USE OWN NAV'. I TURNED R TO 120 DEGS SO AS TO EVENTUALLY INTERCEPT THE 133 BNA R, REMAINING AT 3000' AND UNDER THE CTL OF NASHVILLE DEP. AT APPROX XA:40 LCL TIME THE DEP CTLR CALLED '...TFC 12 O'CLOCK, 2 MI, HDG SW, TYPE AND ALT UNKNOWN'. I REPLIED, 'LOOKING'. I SAW NO TFC, HOWEVER, AND CONTINUED LOOKING. PERHAPS A MIN LATER, I OBSERVED A HIGH WING SINGLE ENG ACFT, WHITE WITH DARK TRIM, PASS DIRECTLY BENEATH ME, HDG SW, AND I BELIEVE, DSNDING. I ADVISED DEP, AND UPON QUERY STATED THE DISTANCE BELOW ME WAS MAYBE 500'. IN RETROSPECT, I FEEL THE SEP WAS A GOOD BIT LESS.

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.