Narrative:

While cruising at 5500' MSL en route from friday harbor to bfi, I experienced a failure of my primary navigation radio, a narco RNAV. At the time I was in contact with ZSE for VFR flight following. In the process of determining the problem I noticed my headsets were receiving audio (and not transmitting) from communication 2 and navigation 2 only. I then tested and reset the panel switches in an effort to bring communication 1 back on-line. Communication 1 came back on-line, however navigation 1 (RNAV) remained inoperative. As communication 1 came back on-line, I heard ZSE call, stating this was the fourth call. I had maintained a visibility scan during our radio silence and there was not any traffic conflict. ZSE cleared me to operate within the TCA and requested I contact sea approach. At this time, I was approximately 1.5 mi and 500' within the sea TCA. Mode C was operating normally. Had the problem arose during the day or during a busy traffic period I believe I would have noticed the communication 1 problem earlier, but since radio chatter was light that evening I did not suspect a problem. Once I determined there was a communication problem, I thought I might have to squawk 7600' if I couldn't fix the transmitting problem within 30 seconds. I was aware of my position and did become concerned since the TCA was so close and I had not received clearance. Callback conversation with reporter revealed the following: continued flight into TCA while trying to determine radio problem is major error. Communication loss was very brief, clearance was very prompt.

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Original NASA ASRS Text

Title: RADIO PROBLEM CAUSED DISTR AND PLT PENETRATED TCA BEFORE RECEIVING CLRNC.

Narrative: WHILE CRUISING AT 5500' MSL ENRTE FROM FRIDAY HARBOR TO BFI, I EXPERIENCED A FAILURE OF MY PRIMARY NAV RADIO, A NARCO RNAV. AT THE TIME I WAS IN CONTACT WITH ZSE FOR VFR FLT FOLLOWING. IN THE PROCESS OF DETERMINING THE PROB I NOTICED MY HEADSETS WERE RECEIVING AUDIO (AND NOT XMITTING) FROM COM 2 AND NAV 2 ONLY. I THEN TESTED AND RESET THE PANEL SWITCHES IN AN EFFORT TO BRING COM 1 BACK ON-LINE. COM 1 CAME BACK ON-LINE, HOWEVER NAV 1 (RNAV) REMAINED INOP. AS COM 1 CAME BACK ON-LINE, I HEARD ZSE CALL, STATING THIS WAS THE FOURTH CALL. I HAD MAINTAINED A VIS SCAN DURING OUR RADIO SILENCE AND THERE WAS NOT ANY TFC CONFLICT. ZSE CLRED ME TO OPERATE WITHIN THE TCA AND REQUESTED I CONTACT SEA APCH. AT THIS TIME, I WAS APPROX 1.5 MI AND 500' WITHIN THE SEA TCA. MODE C WAS OPERATING NORMALLY. HAD THE PROB AROSE DURING THE DAY OR DURING A BUSY TFC PERIOD I BELIEVE I WOULD HAVE NOTICED THE COM 1 PROB EARLIER, BUT SINCE RADIO CHATTER WAS LIGHT THAT EVENING I DID NOT SUSPECT A PROB. ONCE I DETERMINED THERE WAS A COM PROB, I THOUGHT I MIGHT HAVE TO SQUAWK 7600' IF I COULDN'T FIX THE XMITTING PROB WITHIN 30 SECS. I WAS AWARE OF MY POS AND DID BECOME CONCERNED SINCE THE TCA WAS SO CLOSE AND I HAD NOT RECEIVED CLRNC. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: CONTINUED FLT INTO TCA WHILE TRYING TO DETERMINE RADIO PROB IS MAJOR ERROR. COM LOSS WAS VERY BRIEF, CLRNC WAS VERY PROMPT.

Data retrieved from NASA's ASRS site as of August 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.