Narrative:

I was acting as the PF and the first officer was handling communications with ATC. Unknown to me, my communication receiver was intermittent due to a fault in my avionics control panel. As a result, I did not hear an off course vector that was assigned to my flight by ZTL. The first officer did hear and acknowledge the clearance, but he did not notice that I failed to respond by initiating the assigned heading change. Since the first officer assumed that I heard the clearance, he continued to perform other prelndg functions (calling in-range, etc). I did not notice the first officer had been speaking on the radio due to cockpit noise and the fact that we use headset/mikes instead of hand held mikes. ATC subsequently noted our failure to turn and issued a new heading and altitude to avoid traffic. At that point, it became obvious that I could not hear ATC, the first officer took control of the aircraft and complied with the instructions. A contributing factor was the high workload prior to landing that kept the first officer from challenging my failure to comply with the original off-course vector. While we have become very careful about verifying altitude changes, we do not handle lateral flight plan modifications in the same manner. Forcing both crew members to verify lateral as well as vertical clrncs would immediately detect communication problems like the one I encountered.

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Original NASA ASRS Text

Title: NON ADHERENCE TO ATC CLRNC DUE TO A RADIO EQUIP PROB.

Narrative: I WAS ACTING AS THE PF AND THE FO WAS HANDLING COMS WITH ATC. UNKNOWN TO ME, MY COM RECEIVER WAS INTERMITTENT DUE TO A FAULT IN MY AVIONICS CTL PANEL. AS A RESULT, I DID NOT HEAR AN OFF COURSE VECTOR THAT WAS ASSIGNED TO MY FLT BY ZTL. THE FO DID HEAR AND ACKNOWLEDGE THE CLRNC, BUT HE DID NOT NOTICE THAT I FAILED TO RESPOND BY INITIATING THE ASSIGNED HDG CHANGE. SINCE THE FO ASSUMED THAT I HEARD THE CLRNC, HE CONTINUED TO PERFORM OTHER PRELNDG FUNCTIONS (CALLING IN-RANGE, ETC). I DID NOT NOTICE THE FO HAD BEEN SPEAKING ON THE RADIO DUE TO COCKPIT NOISE AND THE FACT THAT WE USE HEADSET/MIKES INSTEAD OF HAND HELD MIKES. ATC SUBSEQUENTLY NOTED OUR FAILURE TO TURN AND ISSUED A NEW HDG AND ALT TO AVOID TFC. AT THAT POINT, IT BECAME OBVIOUS THAT I COULD NOT HEAR ATC, THE FO TOOK CTL OF THE ACFT AND COMPLIED WITH THE INSTRUCTIONS. A CONTRIBUTING FACTOR WAS THE HIGH WORKLOAD PRIOR TO LNDG THAT KEPT THE FO FROM CHALLENGING MY FAILURE TO COMPLY WITH THE ORIGINAL OFF-COURSE VECTOR. WHILE WE HAVE BECOME VERY CAREFUL ABOUT VERIFYING ALT CHANGES, WE DO NOT HANDLE LATERAL FLT PLAN MODIFICATIONS IN THE SAME MANNER. FORCING BOTH CREW MEMBERS TO VERIFY LATERAL AS WELL AS VERT CLRNCS WOULD IMMEDIATELY DETECT COM PROBS LIKE THE ONE I ENCOUNTERED.

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.