CLOSE PROX SUP ACR-WDB GA-SMA EAST OF LCK.

Narrative

DEPARTING RICKENBACKER FOR NAVY NORFOLK IN CONTACT WITH LOCKBORNE DEP CTL 119.15 FLYING 090 DEG RADAR VECTOR. GIVEN CLRNC TO CLB FROM 4000 TO 7000'. GIVEN TFC CALL 2 O'CLOCK; 3 MI; ALT UNKNOWN. DID NOT SEE TFC. SCATTERED CLOUDS ABOVE US; ANOTHER TFC CALL AT 12:30; 1 MI; AS WE WERE CLBING THROUGH 4500'. WE SPOTTED TFC ABOVE US HDG N ON WHAT APPEARED TO BE A VERY CLOSE MERGE PLOT. THE CAPT NOSED THE ACFT OVER INTO A DSCNT TO REMAIN BELOW THE OTHER ACFT UNTIL WE HAD PASSED IT; THEN WE CONTINUED OUR CLB TO 7000'. THE DEP CTLR ASKED IF WE WOULD LIKE THE INCIDENT INVESTIGATED AFTER WE INFORMED HIM OF WHAT WE HAD JUST EXPERIENCED WITH THE SINGLE ENG ACFT. WE INFORMED HIM THAT WE WOULD AS THIS COULD HAVE VERY NEARLY ENDED IN A MOST DISASTROUS SITUATION AND NEEDS TO BE ADDRESSED BOTH WITH THE GA COMMUNITY AND THE ACR'S THAT OPERATE OUT OF THE ARPTS IN THIS AREA. WHY WERE WE GIVEN CLRNC TO CLB WHEN TFC ON A PERPENDICULAR COURSE WITH AN UNKNOWN ALT WAS SO CLOSE? WHY WAS THIS ACFT; SO CLOSE TO RICKENBACKER; NOT IN COM WITH ATC OR RPTING ITS ALT VIA MODE C?