NMAC BTWN AN LTT ACR AND AN SMA SINGLE ENG LAND TRAINING ACFT IN VFR CONDITIONS NEAR AN UNCTLED ARPT.

Narrative

ON JUL/THU/93; WE RECEIVED OUR CLRNC ON THE GND AT SHD FROM ZDC 135.40. WE WERE RELEASED BY CTR. WE ANNOUNCED TKOF ON RWY 23 WITH A L DOWNWIND DEP TO THE NE. THIS WAS XMITTED ON UNICOM. NO OTHER ACFT RESPONDED. ON CLBOUT APPROX 2500 FT WE CONTACTED CTR. WE WERE TOLD 'RADAR CONTACT.' WE THEN XMITTED AGAIN ON UNICOM OUR POS. NO OTHER ACFT RESPONSE. AT APPROX 4500-5000 FT (WE WERE CLRED TO 6000 FT) OUT OF NOWHERE CAME A SINGLE ENG ACFT AT 12 O'CLOCK. THE FO (PF) IMMEDIATELY PITCHED THE ACFT OVER. THE SMA WENT OVER US. THIS WAS VERY CLOSE. THERE IS NO DOUBT IN MY MIND THAT IF WE HAD NOT PITCHED DOWN; WE WOULD HAVE COLLIDED. THE DISTANCE WAS ABOUT 30 FT OR LESS. I ASKED CTR IF THEY HAD THE SINGLE ENG LAND SMA ON RADAR. HE SAID NO. I THEN SAID WE HAD HAD A NEAR MISS. HE STERNLY REPLIED HE HAD NO TFC. I THEN HEARD THE SMA ON UNICOM. I ASKED IF THEY HAD SEEN US. THE REPLY WAS 'YEAH; WE SAW YOU GO UNDER US.' I STATED WE NEARLY COLLIDED. HE SAID HE WAS AN INSTRUCTOR WITH AN INST STUDENT UNDER THE HOOD. WE CONTINUED THE FLT TO BWI. COMMENTS: THIS ACFT MADE NO RADIO CALLS ON SHD UNICOM. ZDC HAD US IN RADAR CONTACT AT 2500 FT BUT 'HAD NO CONTACT OF AN ACFT AT 4500 FT!' SVC BY ATC FOR UNCTLED FIELDS IS POOR.