PRIVATE PLT OF SMA TRAINING ACFT INADVERTENTLY PENETRATED A TCA WHILE APCHING AN ARPT INSIDE AND UNDERNEATH THE TCA.

Narrative

I WAS FLYING FROM CARBONDALE; IL; TO SPIRIT OF ST LOUIS ARPT. WHEN I GOT NEAR THE TCA I DECIDED TO NAV WITH THE TERMINAL AREA CHART INSTEAD OF THE SECTIONAL. THIS WAS THE FIRST TIME I HAD EVER USED A TCA FOR NAV PURPOSES; SO I WAS NOT VERY EXPERIENCED WITH IT. WHEN I FIRST ENTERED THE TCA VICINITY; I CALLED ST LOUIS APCH AND GOT FLT FOLLOWING. WHEN I WAS ABOUT 10 NM SE OF SPIRIT; I TERMINATED RADAR SVC AND CALLED SPIRIT TWR AFTER LISTENING TO THE ATIS. I TOLD TWR THAT 'I WAS 10 MI SE; INBOUND TO LAND WITH THE INFO.' A FEW MINS LATER; THE TWR CALLED ME AND ASKED MY POS. I THOUGHT I WAS ABOUT 6 MI SE; BUT ACTUALLY I WAS ABOUT 5 OR 6 MI NE; AND FLYING THROUGH THE TCA. SINCE I WAS UNFAMILIAR WITH THE AREA AND I WAS INEXPERIENCED WITH THE TERMINAL AREA CHART I SOMEHOW GOT SOMEWHAT LOST. THE REASON THAT I THOUGHT I WAS SE OF SPIRIT HAS TO DO WITH THE 2 DIFFERENT SCALES OF THE TCA AND THE SECTIONAL. I WAS SO ACCUSTOMED TO REFING LANDMARKS WITH A SECTIONAL THAT I WAS SELF-CONSCIOUSLY DOING THE SAME WITH THE TCA. THERE IS A SMALL BEND IN A RIVER WHICH IS 9 NM; 143 DEGS FROM SPIRIT -- SE OF THE ARPT -- THAT IS WHERE I THOUGHT I WAS. ACTUALLY; I WAS OVER THE LARGER RIVER BEND ABOUT 5 NM; 77 DEGS FROM SPIRIT; AT 2500 FT MSL; IN THE TCA. WHEN SPIRIT TWR TOLD ME WHERE I WAS; THEY SUGGESTED THAT I DSND TO 1900 FT AND THAT THE ARPT WAS BEHIND ME AND TO THE L. SO; I TURNED AROUND AND TRIED LOOKING FOR THE ARPT; BUT I COULD NOT FIND IT. IT WAS SO DIFFICULT TO SEE THAT I DIDN'T FIND IT UNTIL I WAS ABOUT 3 MI AWAY. I THINK SOMETHING SHOULD BE DONE TO MAKE THE ARPT MORE VISIBLE FROM THE AIR; IT WAS VERY DIFFICULT TO FIND.