Narrative:

Took off west/O clearance. Advised by departure control. No action taken. No evasive action required. No landing aircraft. Caused by misunderstanding tower, I thought I was cleared. I have had radio problems and plane has been in several times in last 3 months to correct them. This was first flight to test most recent repairs. When the headset boom microphone is plugged in, there has been a tendency to block out all reception from 5 to 10 mins after engine start. Avionics people went on a test flight with me 2 weeks ago and believe they identified the problem (a ground) and corrected it. Departure control advised I was transmitting on one frequency and receiving on another. With the audio switch panel configured for the 'both' switch off and the other in 'automatic' this should not happen. It will be checked out again thoroughly before next flight.

Google
 

Original NASA ASRS Text

Title: TKOF WITHOUT CLRNC.

Narrative: TOOK OFF W/O CLRNC. ADVISED BY DEP CTL. NO ACTION TAKEN. NO EVASIVE ACTION REQUIRED. NO LNDG ACFT. CAUSED BY MISUNDERSTANDING TWR, I THOUGHT I WAS CLRED. I HAVE HAD RADIO PROBS AND PLANE HAS BEEN IN SEVERAL TIMES IN LAST 3 MONTHS TO CORRECT THEM. THIS WAS FIRST FLT TO TEST MOST RECENT REPAIRS. WHEN THE HEADSET BOOM MIKE IS PLUGGED IN, THERE HAS BEEN A TENDENCY TO BLOCK OUT ALL RECEPTION FROM 5 TO 10 MINS AFTER ENG START. AVIONICS PEOPLE WENT ON A TEST FLT WITH ME 2 WKS AGO AND BELIEVE THEY IDENTIFIED THE PROB (A GND) AND CORRECTED IT. DEP CTL ADVISED I WAS TRANSMITTING ON ONE FREQ AND RECEIVING ON ANOTHER. WITH THE AUDIO SWITCH PANEL CONFIGURED FOR THE 'BOTH' SWITCH OFF AND THE OTHER IN 'AUTO' THIS SHOULD NOT HAPPEN. IT WILL BE CHKED OUT AGAIN THOROUGHLY BEFORE NEXT FLT.

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.