PA44 EXECUTES A R 360 DEG TURN AFTER ORIGINALLY MISINTERPING ZMA SEQUENCING CLRNC.

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I AM AN MEI GIVING INSTRUCTION TO AN INST APPLICANT. WE WERE DOING A PARTIAL PANEL VOR APCH USING THE COMPASS AND OBS FOR NAV. ZMA GAVE US OUR VECTOR TO INTERCEPT THE FINAL APCH COURSE; 'FLY HDG 140 DEGS; INTERCEPT THE FINAL APCH COURSE (300 DEG RADIAL).' THE STUDENT PLT DID AS REQUESTED; BUT WENT THROUGH THE 300 DEG RADIAL. I ADVISED THE STUDENT TO TURN BACK TO APPROX A 100 DEG HDG TO REINTERCEPT THE COURSE. (AT NO POINT WERE WE WERE FULL-SCALE DEFECTION.) WHILE ON A HDG OF 100 DEGS; ATC ADVISED; 'TURN R TO 090 DEGS AND REINTERCEPT THE COURSE FOR SPACING.' AT THIS POINT; WE WERE STILL TO THE R OF COURSE; SO I THOUGHT THAT ATC HAD MADE AN ERROR AND MEANT TURN L TO 090 DEGS TO INTERCEPT THE 300 DEG RADIAL. THE STUDENT DID THIS (AFTER I ADVISED HIM TO DO SO) AND WE DID IN FACT REINTERCEPT THE COURSE. I THEN ASKED ATC IF IT WAS OK TO PROCEED INBOUND ON THE 300 DEG RADIAL. AT THIS POINT; THE CTLR BECAME UNDERSTANDABLY UPSET BECAUSE HE WANTED US TO BASICALLY MAKE A R 360 DEG TURN. HE ADVISED THAT WE WERE ABOUT TO BREAK THE 2 MI SPACING REQUIREMENT FOR IFR TFC AND THAT I HAD DEVIATED FROM AN ATC INSTRUCTION. AT THIS POINT; I APOLOGIZED FOR THE ERROR I HAD MADE AND PROMPTLY EXECUTED THE R TURN; BACK TO 090 DEGS; AND INTERCEPTED THE COURSE. THE REST OF THE APCH WAS FINE. LOOKING BACK; I SHOULD HAVE NOT ASSUMED THE ATC OPERATOR MADE A MISTAKE AND SHOULD HAVE ASKED HIM TO CLARIFY HIS INSTRUCTIONS. I DO FEEL THAT THIS MISCOM COULD HAVE BEEN AVOIDED IF HE WOULD HAVE SAID 'MAKE A R 360 DEG TURN TO 090 DEGS OR A R 330 DEG TURN TO 090 DEGS AND REINTERCEPT THE FINAL APCH COURSE.' THE LATTER PHRASEOLOGY SEEMS TO BE THE MORE COMMON ONE THAT I HAVE BEEN GIVEN IN SIMILAR SITS.