SMA PLT PERFORMS AN UNAUTH TOUCH-AND-GO AFTER TWR HAD GIVEN CLRNC LNDG.

Narrative

WHILE LNDG ON RWY 12 AT COS I WASN'T SURE IF I HAD BEEN CLRED FOR TOUCH-AND-GO WHICH I THOUGHT I HAD REQUESTED OR FOR FULL STOP. AS I TOUCHED DOWN I TRIED TWICE TO GET CLARIFICATION BUT GOT NO RESPONSE SO I MADE A TOUCH-AND- GO. THIS ACTION TOOK ME ACROSS RWY 17L AT ABOUT 100 FT. I CHKED FOR ANY TFC ON RWY 17L BEFORE ATTEMPTING THE TOUCH-AND-GO AND DIDN'T SEE ANY. AFTER REACHING 400 FT THE CTLR INFORMED ME THAT I HAD BEEN CLRED FOR A FULL STOP AND THAT THE TOUCH-AND-GO WAS UNACCEPTABLE; THAT I SHOULD HAVE REQUESTED THE TOUCH-AND-GO WHEN I CONTACTED APCH. A CONTRIBUTING FACTOR WAS THAT I HAD INTENDED THE TOUCH-AND-GO AT COS BEFORE LEAVING MY HOME ARPT AND HAD PLANNED MAKING THAT REQUEST. AFTER CONTACTING APCH I WAS CLRED FOR RWY 12 WHICH I HAD NOT LANDED ON BEFORE. WHILE ON FINAL I WAS TRIMMING THE ACFT WITH A BUTTON ON THE YOKE WHICH WAS RIGHT ABOVE THE MIKE BUTTON SO THAT WHEN I TRIED TO XMIT AS I TOUCHED DOWN I MAY HAVE HAD MY FINGER STILL ON THE TRIM BUTTON. THIS MAY HAVE BEEN THE REASON I DIDN'T GET A RESPONSE FROM TWR. I WILL ENSURE I HAVE THE APPROPRIATE CLRNC IN THE FUTURE. WILL ALSO SEE IF THE MIKE BUTTON CAN BE RELOCATED.