SMA HAS NMAC WITH DC9.

Narrative

I WAS ENRTE FROM PLYMOUTH; MA; TO WESTERLY; RI; WITH A STUDENT ON A XCOUNTRY FLT; LEVEL AT 4500 FT MSL; WITH ALL EQUIP WORKING ON TKOF. ABOUT 20 NM E OF PROVIDENCE; RI; I CALLED PVD APCH TO OBTAIN FLT FOLLOWING. THE CTLR GAVE ME A XPONDER CODE AND TOLD ME TO IDENT. I SQUAWKED THE CODE AND PUSHED THE INDENT BUTTON. THEN I WENT BACK TO GIVING INSTRUCTION TO MY STUDENT. AROUND 5-6 MINS LATER; IT DAWNED ON ME THAT I DID NOT HEAR THE CTLR VERIFY THAT I WAS RADAR CONTACT. SO I CALLED APCH CTL AGAIN AND ASKED TO VERIFY THAT I WAS IN RADAR CONTACT. BY NOW; I WAS OVER PVD CLASS C AIRSPACE LEVEL 4500 FT MSL AND ABOUT 7 NM SE OF PVD ARPT. THE CTLR CAME BACK AND TOLD ME THAT THERE WAS NO SECONDARY OR PRIMARY RETURN ON THE RADAR SCOPE AND TO REMAIN CLR OF PVD CLASS C AIRSPACE. NOW; I WAS ABOUT 2 NM S OF QUONSET STATE ARPT AND I ELECTED TO CONTINUE ON COURSE; FIGURING IT WAS ABOUT THE SAME DISTANCE TO CONTINUE STRAIGHT AHEAD THAN TURNING L TO GET BEYOND THE 10 MI RING OF THE CLASS C AIRSPACE; BEING THAT I NOW DID NOT HAVE AN OPERABLE MODE C XPONDER. CONTINUING ENRTE; ABOUT 6 NM SW OF QUONSET ARPT; TFC WAS SPOTTED AT 12 O'CLOCK AT THE SAME ALT AS MY ACFT. I WAS FORCED TO TAKE CORRECTIVE ACTION BY BANKING TO THE R AND DSNDING 300 FT WHEN A DC-9 FLEW DIRECTLY OVERHEAD. THE DC-9 WAS AT 4500 FT MSL (WHICH WAS MY VFR ALT FLYING WBOUND) AND HE WAS TRAVELLING EBOUND. I DON'T KNOW IF THE DC-9 PLT EVER SAW ME; BECAUSE HE DID NOT SEEM TO TAKE ANY CORRECTIVE ACTION. I WOULD RECOMMEND THAT WHEN AN ACFT LOSES ITS MODE C XPONDER AND ESPECIALLY WHEN THEY LOSE IT OVER CLASS C OR B AIRSPACE; THAT THE CTLR DOES NOT JUST HASTILY KICK ACFT OUT OF THE AIRSPACE; BUT MAKE AN ATTEMPT TO KEEP UP POS RPTING TO REDUCE THE POSSIBILITIES OF CLOSE CALLS LIKE THIS ONE. FURTHERMORE; UNLESS THE DC- 9 WAS DSNDING; HE SHOULD NOT HAVE BEEN FLYING ON A WBOUND VFR ALT WHEN FLYING EBOUND. AS SHOWN HERE; IT JUST INCREASES THE POSSIBILITY (ALTHOUGH REMOTE) OF A MIDAIR COLLISION.