Narrative:

I departed gainesville regional airport without permission of ground and tower. This was accidental caused by a malfunction of the microphone. I was acting as the PIC of the flight even though the instrument flight plan was filed under another pilot's name. I was also renting the plane for the return flight. As I was performing the preflight of the aircraft, I asked the other pilot to file an instrument flight plan for me. He did so accidentally under his own name even though he was flying in the back seat as a passenger. I was attempting to contact ground and tower from the FBO ramp, and I received no reply. I assumed the airfield was uncontrolled at the time because of a lack of communication on this frequency. The problem of no other traffic also complicated matters. Since no one else was in the vicinity talking to ground or the tower we didn't pick up their transmissions. I then called the unicom frequency and advised traffic that I was departing on runway 6. I then tried to contact jacksonville approach and was unable to transmit on this frequency until I used a pair of headsets. This made me realize that the microphone was inoperative and that I had taken off without clearance. I believe this occurrence could have been avoided if I tried to troubleshoot this problem on the ground. I should have stopped the aircraft and called the FSS to see if the field was inactive instead of assuming so.

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Original NASA ASRS Text

Title: PLT OF SMA TOOK OFF WITHOUT CONTACTING TWR. PLT ASSUMED TWR WAS NOT ACTIVE. PF NOT NAMED AS PLT ON IFR PLAN.

Narrative: I DEPARTED GAINESVILLE REGIONAL ARPT WITHOUT PERMISSION OF GND AND TWR. THIS WAS ACCIDENTAL CAUSED BY A MALFUNCTION OF THE MICROPHONE. I WAS ACTING AS THE PIC OF THE FLT EVEN THOUGH THE INST FLT PLAN WAS FILED UNDER ANOTHER PLT'S NAME. I WAS ALSO RENTING THE PLANE FOR THE RETURN FLT. AS I WAS PERFORMING THE PREFLT OF THE ACFT, I ASKED THE OTHER PLT TO FILE AN INST FLT PLAN FOR ME. HE DID SO ACCIDENTALLY UNDER HIS OWN NAME EVEN THOUGH HE WAS FLYING IN THE BACK SEAT AS A PAX. I WAS ATTEMPTING TO CONTACT GND AND TWR FROM THE FBO RAMP, AND I RECEIVED NO REPLY. I ASSUMED THE AIRFIELD WAS UNCTLED AT THE TIME BECAUSE OF A LACK OF COM ON THIS FREQ. THE PROBLEM OF NO OTHER TFC ALSO COMPLICATED MATTERS. SINCE NO ONE ELSE WAS IN THE VICINITY TALKING TO GND OR THE TWR WE DIDN'T PICK UP THEIR TRANSMISSIONS. I THEN CALLED THE UNICOM FREQ AND ADVISED TFC THAT I WAS DEPARTING ON RWY 6. I THEN TRIED TO CONTACT JACKSONVILLE APCH AND WAS UNABLE TO XMIT ON THIS FREQ UNTIL I USED A PAIR OF HEADSETS. THIS MADE ME REALIZE THAT THE MICROPHONE WAS INOP AND THAT I HAD TAKEN OFF WITHOUT CLRNC. I BELIEVE THIS OCCURRENCE COULD HAVE BEEN AVOIDED IF I TRIED TO TROUBLESHOOT THIS PROBLEM ON THE GND. I SHOULD HAVE STOPPED THE ACFT AND CALLED THE FSS TO SEE IF THE FIELD WAS INACTIVE INSTEAD OF ASSUMING SO.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.