WHILE TRANSITING CLASS D AIRSPACE; A C172 PLT HAS A CLOSE ENCOUNTER WITH A JET ACFT.

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I WAS FLYING ORIENTATION FLTS IN A CESSNA SKYHAWK. I DEPARTED ZZZ ENRTE TO (TAN) TAUNTON; MA. I CONTACTED (HYA) HYANNIS TWR AND RPTED 8 MI E AND WOULD LIKE TO TRANSITION HYA AIRSPACE ALONG THE N SHORE AT 2500 FT. I WAS CLRED FOR THE TRANSITION AS REQUESTED. WHEN I WAS APPROX HALFWAY THROUGH THE CLASS D AIRSPACE I SAW A BUSINESS CLASS JET AT MY 8 O'CLOCK POS; IN A CLBING R TURN THAT APPEARED TO BE NO MORE THAN 200-300 FT AWAY. BEFORE I COULD TAKE ANY EVASIVE ACTION THE JET WAS PAST US TRAVELING AT A VERY HIGH RATE OF SPD. I ONLY SAW THE TFC FOR A SPLIT SECOND AS IT WAS EXTREMELY CLOSE AND FAST; IT APPEARED AS IF THE JET WOULD HAVE COLLIDED WITH US IF IT WEREN'T CLBING. I WAS MONITORING HYA TWR FREQ THE ENTIRE TIME I WAS IN CLASS D AIRSPACE; TO ME THE CTLR SOUNDED MODERATELY BUSY WORKING BOTH AIR AND GND SIMULTANEOUSLY. I DIDN'T HEAR ANY TFC ALERTS FOR EITHER THE DEPARTING JET TFC OR MYSELF. I'M NOT EVEN SURE THE JET TFC EVER SAW ME. IF THEY DID; THE TURN MAY HAVE BEEN EVASIVE ACTION AND THEY MUST HAVE SEEN ME AT THE LAST POSSIBLE SECOND TO AVOID A COLLISION. I DID NOT CONTACT THE TWR TO INFORM THEM OF THE NEAR MISS AND DON'T KNOW IF THEY EVEN REALIZED THE POTENTIAL DISASTER. I ASSUME WHEN IN CTLED AIRSPACE THE CTLR CTLS? WAS THE CTLR TOO BUSY WITH GND CTL? I AM RPTING THIS INCIDENT TO HOPEFULLY AVOID ANY FUTURE DISASTERS.