AN SMA PLT TOOK THE RWY FOR TKOF WITHOUT PROPER CLRNC.

Narrative

ON THE AFTERNOON OF SEP/SAT/93 I HAD VISITED THE DEN FSS FOR A WX BRIEFING AND HAD FILED AN IFR FLT PLAN. ON MY INITIAL CALLUP TO THE TWR; I WAS ADVISED THAT IT HAD MY CLRNC AND WAS ASKED IF I WAS READY TO COPY. I COPIED THE CLRNC AS I WAS TAXIING OUT OF THE TRANSIENT PARKING AREA AND THE TWR INFORMED ME THAT MY READBACK WAS CORRECT. I WAS DIRECTED TO TAXI TO RWY 35R. UPON ARRIVING AT THE S END OF 35R; I FOUND MYSELF TO BE #2 BEHIND AN SMA. I COMPETED MY PRE-TKOF CHKLIST AND RUNUP AND CALLED THE TWR INDICATING THAT I WAS READY FOR TKOF. THE TWR THEN CALLED THE SMA AND INQUIRED HOW MUCH MORE TIME THE PLT WOULD NEED BEFORE HE WAS READY TO DEPART. WHEN THE SMA RESPONDED THAT IT WOULD REQUIRE 2 MORE MINS BEFORE IT WOULD BE READY FOR DEP; THE TWR ASKED ME IF I WOULD BE ABLE TO TAXI AROUND THE SMA AND ONTO THE RWY. I RESPONDED THAT THERE WAS INSUFFICIENT ROOM BUT THAT I HAD ROOM TO DO A 180 AND TO RETURN TO THE NEXT TXWY TO THE N. THE TWR THEN INSTRUCTED ME TO DO SO AND; I THINK; CLRED ME FOR TKOF. I IMMEDIATELY DID AS INSTRUCTED. AS I BEGAN MY TKOF ROLL; I HEARD THE TWR CLR THE SMA FOR TKOF AND THEN REALIZED THAT SOMETHING WAS AMISS. THE TWR THEN INSTRUCTED ME TO ABORT MY TKOF AND TO EXIT THE RWY. I DID SO. IT ALSO AMENDED THE SMA'S INSTRUCTIONS TO A REQUEST THAT IT TAXI INTO POS AND HOLD. AS SOON AS I WAS CLR OF THE RWY; THE SMA WAS CLRED FOR TKOF AND DEPARTED. AS I WAS RETURNING TO THE S END OF RWY 35R; THE TWR FIRST INFORMED ME THAT IT HAD NOT YET RECEIVED MY RELEASE FROM ATC. BY THE TIME THAT I HAD RETURNED TO THE HOLD LINE FOR 35R; THE TWR ISSUED AN AMENDMENT TO MY EARLIER-RECEIVED CLRNC AND CLRED ME FOR TKOF. I BELIEVE THAT I WAS AT FAULT IN MISUNDERSTANDING THE TWR'S INSTRUCTIONS TO INCLUDE A TKOF CLRNC. I AM STILL PUZZLED; HOWEVER; TO THINK THAT THE TWR WOULD INQUIRE OF THE SMA AS TO THE AMOUNT OF TIME IT WOULD NEED BEFORE IT WOULD BE READY TO DEPART AND TO THEN INSTRUCT ME TO TAXI AROUND HIM OR; AS IT HAPPENED; TO TRAVEL TO THE NEXT INTXN NORTH WHEN IT KNEW; AND I DID NOT; THAT ATC HAD NOT YET AUTHORIZED THE RELEASE OF MY ACFT! I FEEL THAT THIS ENTIRE SIT WOULD NOT HAVE OCCURRED IF THE TWR HAD SIMPLY INFORMED ME IMMEDIATELY THAT IT WAS STILL WAITING FOR MY RELEASE FROM ATC WHEN I CALLED TO INDICATE THAT I WAS READY FOR TKOF.