Flight crew of an light transport has an erratic volume control problem on communication radio. Whil...

Attributes
ACN	422794
Time
Date	199812
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : mcn
State Reference	GA
Altitude	msl bound lower : 18000 msl bound upper : 18000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Navigation In Use	Other
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 200 flight time total : 15000 flight time type : 6000
ASRS Report	422794
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : became reoriented other
Consequence	Other
Supplementary
Air Traffic Incident	Pilot Deviation

Narrative:

Cruise flight at FL180 from vld to atl. I had noted on an earlier leg that the volume control on my audio panel was erratic. The volume would unpredictably rise or fall with no input from me. My first officer and I were engaged in an intense conversation and I suspect that my volume became low and therefore I missed center calling us. As the aircraft neared mcn VORTAC (where we normally would cross at 11000 ft) I realized that something was wrong. I stopped the conversation and called ATC. They confirmed that we had missed several calls and proceeded to vector us around as necessary in order to descend us to the proper altitude for the arrival. I apologized and told them I had a suspect audio panel. The rest of the flight was normal and my volume continued to fluctuate. Upon landing, we reported it to maintenance and it was eventually replaced. The malfunctioning audio panel contributed to this communication breakdown, but I am acutely aware that if my first officer and I had not been so involved in our conversation that one of us would've heard ATC calling, or I would've noticed the reduced volume. Also contributing was my decision not to have the panel repaired after our first becoming aware of the problem. (I wanted to wait until we had a break long enough so we would not be delayed.) I thought it was not serious and that 'I could live with it for a round trip or two.' this was a valuable lesson and I'll endeavor to avoid such mistakes in the future.

Original NASA ASRS Text

Title: FLC OF AN LTT HAS AN ERRATIC VOLUME CTL PROB ON COM RADIO. WHILE ENGAGED IN CONVERSATION WITH FO, THE CREW FAILS TO HEAR ATC CALLS. THEY FINALLY REALIZE SOMETHING IS WRONG AND CONTACT ATC.

Narrative: CRUISE FLT AT FL180 FROM VLD TO ATL. I HAD NOTED ON AN EARLIER LEG THAT THE VOLUME CTL ON MY AUDIO PANEL WAS ERRATIC. THE VOLUME WOULD UNPREDICTABLY RISE OR FALL WITH NO INPUT FROM ME. MY FO AND I WERE ENGAGED IN AN INTENSE CONVERSATION AND I SUSPECT THAT MY VOLUME BECAME LOW AND THEREFORE I MISSED CTR CALLING US. AS THE ACFT NEARED MCN VORTAC (WHERE WE NORMALLY WOULD CROSS AT 11000 FT) I REALIZED THAT SOMETHING WAS WRONG. I STOPPED THE CONVERSATION AND CALLED ATC. THEY CONFIRMED THAT WE HAD MISSED SEVERAL CALLS AND PROCEEDED TO VECTOR US AROUND AS NECESSARY IN ORDER TO DSND US TO THE PROPER ALT FOR THE ARR. I APOLOGIZED AND TOLD THEM I HAD A SUSPECT AUDIO PANEL. THE REST OF THE FLT WAS NORMAL AND MY VOLUME CONTINUED TO FLUCTUATE. UPON LNDG, WE RPTED IT TO MAINT AND IT WAS EVENTUALLY REPLACED. THE MALFUNCTIONING AUDIO PANEL CONTRIBUTED TO THIS COM BREAKDOWN, BUT I AM ACUTELY AWARE THAT IF MY FO AND I HAD NOT BEEN SO INVOLVED IN OUR CONVERSATION THAT ONE OF US WOULD'VE HEARD ATC CALLING, OR I WOULD'VE NOTICED THE REDUCED VOLUME. ALSO CONTRIBUTING WAS MY DECISION NOT TO HAVE THE PANEL REPAIRED AFTER OUR FIRST BECOMING AWARE OF THE PROB. (I WANTED TO WAIT UNTIL WE HAD A BREAK LONG ENOUGH SO WE WOULD NOT BE DELAYED.) I THOUGHT IT WAS NOT SERIOUS AND THAT 'I COULD LIVE WITH IT FOR A ROUND TRIP OR TWO.' THIS WAS A VALUABLE LESSON AND I'LL ENDEAVOR TO AVOID SUCH MISTAKES IN THE FUTURE.

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.

Flight crew of an light transport has an erratic volume control problem on communication radio. While engaged in conversation with first officer, the crew fails to hear ATC calls. They finally realize something is wrong and contact ATC.