Narrative:

I was flying at 4000 ft, heading 090 degrees, being radar vectored to the ILS at sna on an IFR flight from cma. The WX in the area (sna ATIS) was visibility 9 mi, scattered clouds at 2000 ft, ceiling 2600 ft. The socal controller instructed me to turn right heading 170 degrees, cleared me for the ILS approach, and instructed me to maintain 3000 ft until established on the approach. I initiated the turn, keyed the microphone button to acknowledge the transmission, and found that I was unable to transmit (I couldn't even hear myself in my headset). I immediately tried again, with the same result. Thinking that the problem was in the microphone button on my yoke. I then tried the microphone button on the other yoke. The result was the same. During this short time, the distraction caused me to inadvertently slow the airplane's rate of turn. The controller called me again, issuing the same instructions. I tried acknowledging once more using my microphone button, again unsuccessfully. I then switched to the #1 radio and successfully acknowledged the controller's third transmission. He complained that he had called me 3 times because he did not see me start the turn. I told him that I had responded to him each time but that although I could hear him, he could not hear me. At this point in time, my CDI showed that I was about to join the localizer. Socal said that I was about to cross through the localizer, so he gave me a new vector to rejoin it. Shortly thereafter, he handed me off to sna tower. As I continued the approach, I switched back to my #2 radio and asked the tower how they read me. The tower responded that my transmission was readable but very scratchy. My #2 transmitter was obviously not working properly and undoubtedly had failed transiently when I had tried to acknowledge socal's clearance. The transmitter failure set the stage for confusion in controller/pilot understanding. It couldn't have happened at a worse time, that of being radar vectored from a point near the final approach fix for the ILS in WX that involved IMC. I was responsible for the controller's uncertainty over whether I had received his clearance instructions by forgetting the axiom, 'aviate, navigation, communicate.' I should have made my first priority that of flying and navigating the airplane to the 170 degree heading and executing the intercept of the localizer. My secondary priority should have been troubleshooting the transmitter failure and re-establishing communications with socal. I, instead, reversed these priorities and placed that of restoring communication at the top of the list. Had I not done so, the controller would have observed the expected heading change in a timely fashion and would have been assured that I received his first transmission. He undoubtedly would have been less concerned about not immediately receiving my verbal acknowledgement. In short, my having attended to the proper execution of the heading change would have served in this situation as the acknowledgement that I was otherwise too intent on delivering verbally. This is a lesson well learned. I will not repeat this mistake again.

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Original NASA ASRS Text

Title: A LOW TIME PVT FLYING IN MIXED CONDITIONS WHILE ON THE APCH TO SNA, INTERMITTENTLY LOST COM WITH SOCAL. THIS DISTR CAUSED HIM TO MAKE A HDG ERROR.

Narrative: I WAS FLYING AT 4000 FT, HDG 090 DEGS, BEING RADAR VECTORED TO THE ILS AT SNA ON AN IFR FLT FROM CMA. THE WX IN THE AREA (SNA ATIS) WAS VISIBILITY 9 MI, SCATTERED CLOUDS AT 2000 FT, CEILING 2600 FT. THE SOCAL CTLR INSTRUCTED ME TO TURN R HDG 170 DEGS, CLRED ME FOR THE ILS APCH, AND INSTRUCTED ME TO MAINTAIN 3000 FT UNTIL ESTABLISHED ON THE APCH. I INITIATED THE TURN, KEYED THE MIKE BUTTON TO ACKNOWLEDGE THE XMISSION, AND FOUND THAT I WAS UNABLE TO XMIT (I COULDN'T EVEN HEAR MYSELF IN MY HEADSET). I IMMEDIATELY TRIED AGAIN, WITH THE SAME RESULT. THINKING THAT THE PROB WAS IN THE MIKE BUTTON ON MY YOKE. I THEN TRIED THE MIKE BUTTON ON THE OTHER YOKE. THE RESULT WAS THE SAME. DURING THIS SHORT TIME, THE DISTR CAUSED ME TO INADVERTENTLY SLOW THE AIRPLANE'S RATE OF TURN. THE CTLR CALLED ME AGAIN, ISSUING THE SAME INSTRUCTIONS. I TRIED ACKNOWLEDGING ONCE MORE USING MY MIKE BUTTON, AGAIN UNSUCCESSFULLY. I THEN SWITCHED TO THE #1 RADIO AND SUCCESSFULLY ACKNOWLEDGED THE CTLR'S THIRD XMISSION. HE COMPLAINED THAT HE HAD CALLED ME 3 TIMES BECAUSE HE DID NOT SEE ME START THE TURN. I TOLD HIM THAT I HAD RESPONDED TO HIM EACH TIME BUT THAT ALTHOUGH I COULD HEAR HIM, HE COULD NOT HEAR ME. AT THIS POINT IN TIME, MY CDI SHOWED THAT I WAS ABOUT TO JOIN THE LOC. SOCAL SAID THAT I WAS ABOUT TO CROSS THROUGH THE LOC, SO HE GAVE ME A NEW VECTOR TO REJOIN IT. SHORTLY THEREAFTER, HE HANDED ME OFF TO SNA TWR. AS I CONTINUED THE APCH, I SWITCHED BACK TO MY #2 RADIO AND ASKED THE TWR HOW THEY READ ME. THE TWR RESPONDED THAT MY XMISSION WAS READABLE BUT VERY SCRATCHY. MY #2 XMITTER WAS OBVIOUSLY NOT WORKING PROPERLY AND UNDOUBTEDLY HAD FAILED TRANSIENTLY WHEN I HAD TRIED TO ACKNOWLEDGE SOCAL'S CLRNC. THE XMITTER FAILURE SET THE STAGE FOR CONFUSION IN CTLR/PLT UNDERSTANDING. IT COULDN'T HAVE HAPPENED AT A WORSE TIME, THAT OF BEING RADAR VECTORED FROM A POINT NEAR THE FINAL APCH FIX FOR THE ILS IN WX THAT INVOLVED IMC. I WAS RESPONSIBLE FOR THE CTLR'S UNCERTAINTY OVER WHETHER I HAD RECEIVED HIS CLRNC INSTRUCTIONS BY FORGETTING THE AXIOM, 'AVIATE, NAV, COMMUNICATE.' I SHOULD HAVE MADE MY FIRST PRIORITY THAT OF FLYING AND NAVING THE AIRPLANE TO THE 170 DEG HDG AND EXECUTING THE INTERCEPT OF THE LOC. MY SECONDARY PRIORITY SHOULD HAVE BEEN TROUBLESHOOTING THE XMITTER FAILURE AND RE-ESTABLISHING COMS WITH SOCAL. I, INSTEAD, REVERSED THESE PRIORITIES AND PLACED THAT OF RESTORING COM AT THE TOP OF THE LIST. HAD I NOT DONE SO, THE CTLR WOULD HAVE OBSERVED THE EXPECTED HDG CHANGE IN A TIMELY FASHION AND WOULD HAVE BEEN ASSURED THAT I RECEIVED HIS FIRST XMISSION. HE UNDOUBTEDLY WOULD HAVE BEEN LESS CONCERNED ABOUT NOT IMMEDIATELY RECEIVING MY VERBAL ACKNOWLEDGEMENT. IN SHORT, MY HAVING ATTENDED TO THE PROPER EXECUTION OF THE HDG CHANGE WOULD HAVE SERVED IN THIS SIT AS THE ACKNOWLEDGEMENT THAT I WAS OTHERWISE TOO INTENT ON DELIVERING VERBALLY. THIS IS A LESSON WELL LEARNED. I WILL NOT REPEAT THIS MISTAKE AGAIN.

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.