LACK OF COMPLETE AND CLR INSTRUCTION FROM CTLRS AND FAILURE TO CONFIRM SUCH RESULTS IN ALTDEV BY PLT OF BE90 ON ZFW.

Narrative

I WAS LOCATED ON 020 DEG RADIAL AND 20 NM FROM THE LUFKIN VOR WHILE AT A CRUISING ALT OF 17000 FT IN ZHU'S AIRSPACE. I WAS ENRTE TO THE SHREVEPORT REGIONAL ARPT IN LOUISIANA AND WAS GIVEN A PLT'S DISCRETION DSCNT TO 13000 FT BY ZHU. ALTHOUGH I WAS NOT CLOSE ENOUGH TO MY DEST TO BEGIN THIS DSCNT; I ACCEPTED BY ACKNOWLEDGING '...PLT'S DISCRETION TO 13000 FT.' A FEW MINS LATER; I WAS TOLD TO CONTACT ZFW ON FREQ 135.1. I CHKED ON WITH ZFW BY SAYING; 'ZFW; KING AIR...LEVEL AT 17000 FT WE HAVE PLT'S DISCRETION TO 13000 FT.' ZFW REPLIED WITH; '...BEGIN A DSCNT TO 16000 FT.' I REPEATED BACK I WAS 'LEAVING 17000 FT FOR 16000 FT' AND I BEGAN A SHALLOW DSCNT. WHEN I WAS APCHING 16000 FT; THE DISTANCE FROM MY DEST WAS CLOSE ENOUGH TO WHERE I WOULD CONTINUE MY DSCNT TO 13000 FT. I CONTINUED AND RESUMED A NORMAL RATE OF DSCNT. WHEN I WAS PASSING THROUGH APPROX 15000 FT; ZFW ASKED WHAT ALT I WAS GOING TO. I REPLIED THAT I WAS DSNDING TO 13000 FT. HE SAID THAT I HAD BEEN ASSIGNED 16000 FT. I REMINDED HIM WHEN I HAD CHKED IN THAT I HAD BEEN ASSIGNED PLT'S DISCRETION TO 13000 FT BY ZHU. HE RESPONDED THAT I HAD READ BACK 16000 FT. THE WX WAS VMC AND I DID NOT SEE ANY TFC THAT WOULD HAVE CAUSED A CONFLICT. HE ALSO NEVER SAID ANYTHING THAT WOULD HAVE INDICTED THERE MIGHT HAVE BEEN A CONFLICT EITHER. I APOLOGIZED FOR THE CONFUSION. WHEN HE ASSIGNED A NEW FREQ CHANGE; I REPEATED THE NEW FREQ AND AGAIN APOLOGIZED FOR THE CONFUSION. HE SAID; 'IT'S ALL RIGHT.' HIS OMISSION OF SAYING; 'DSND AND MAINTAIN 16000 FT' ALLOWED ME TO THINK THAT HE JUST WANTED ME TO LEAVE 17000 FT AND THAT I COULD THEN CONTINUE TO 13000 FT AT MY DISCRETION. MY NORMAL TENDENCY TO CLARIFY HIS INTENTIONS WAS SOMEHOW OVERRULED THAT DAY BY ALLOWING MYSELF TO BE PASSIVE AND BELIEVE THAT IF HE DIDN'T WANT ME BELOW 16000 FT HE WOULD HAVE SAID; 'DSND AND MAINTAIN 16000 FT.' MY OMISSION OF SAYING THAT I WAS 'LEAVING 17000 FT FOR 16000 FT AND PLT'S DISCRETION TO 13000 FT' APPARENTLY MADE A SIMILAR IMPRESSION IN HIS MIND. IN THE FUTURE; I WILL BE MORE DILIGENT IN CLARIFYING ONE ANOTHER'S INTENTIONS.