Narrative:

VHF communications had been poor for about 30 mins, mostly because of thunderstorms in arkansas and missouri, but we had been able to talk to ARTCC well enough to get a vector to ddy, and ATC requested that we climb to FL330 at about the sgf VOR. For 5 mins or so prior to the incident, our frequency was basically unreadable due to a probable stuck microphone, it was not our transmitter causing this. As soon as the stuck microphone problem was corrected, we received a call from ZKC to turn right 30 degrees for traffic, which we did. Within seconds, we received a SELCAL from air carrier Z, who told us to contact ZKC on a new frequency, that there was a traffic conflict, and ZKC could not communicate with us or the other aircraft due to a stuck microphone. It appears that an air carrier Y flight at the same altitude was converging head on during the communications blackout. That crew acted upon a TCASII warning and changed course to avoid a collision. I am not sure how close we came, but after discussing it with ZKC, I do not believe we came close enough to file an FAA near miss report. As far as I know, no one in the air or the ground made an error. The system temporarily failed us, and I am thankful that air carrier Y had an operating TCASII because it saved us all a lot of trouble, to put it mildly. Perhaps until TCASII is universally required, we should all monitor guard channel (121.5 or 243.0) as a backup, as the military currently does. I hope it works better in the civil community than it did while I was in the military, however.

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Original NASA ASRS Text

Title: TCASII OF OTHER ACFT HELPS SAVE THE DAY BY DIRECTING ACFT TO TAKE EVASIVE ACTION ON CONVERGING COURSES.

Narrative: VHF COMS HAD BEEN POOR FOR ABOUT 30 MINS, MOSTLY BECAUSE OF TSTMS IN ARKANSAS AND MISSOURI, BUT WE HAD BEEN ABLE TO TALK TO ARTCC WELL ENOUGH TO GET A VECTOR TO DDY, AND ATC REQUESTED THAT WE CLB TO FL330 AT ABOUT THE SGF VOR. FOR 5 MINS OR SO PRIOR TO THE INCIDENT, OUR FREQ WAS BASICALLY UNREADABLE DUE TO A PROBABLE STUCK MIKE, IT WAS NOT OUR XMITTER CAUSING THIS. AS SOON AS THE STUCK MIKE PROB WAS CORRECTED, WE RECEIVED A CALL FROM ZKC TO TURN R 30 DEGS FOR TFC, WHICH WE DID. WITHIN SECONDS, WE RECEIVED A SELCAL FROM ACR Z, WHO TOLD US TO CONTACT ZKC ON A NEW FREQ, THAT THERE WAS A TFC CONFLICT, AND ZKC COULD NOT COMMUNICATE WITH US OR THE OTHER ACFT DUE TO A STUCK MIKE. IT APPEARS THAT AN ACR Y FLT AT THE SAME ALT WAS CONVERGING HEAD ON DURING THE COMS BLACKOUT. THAT CREW ACTED UPON A TCASII WARNING AND CHANGED COURSE TO AVOID A COLLISION. I AM NOT SURE HOW CLOSE WE CAME, BUT AFTER DISCUSSING IT WITH ZKC, I DO NOT BELIEVE WE CAME CLOSE ENOUGH TO FILE AN FAA NEAR MISS RPT. AS FAR AS I KNOW, NO ONE IN THE AIR OR THE GND MADE AN ERROR. THE SYS TEMPORARILY FAILED US, AND I AM THANKFUL THAT ACR Y HAD AN OPERATING TCASII BECAUSE IT SAVED US ALL A LOT OF TROUBLE, TO PUT IT MILDLY. PERHAPS UNTIL TCASII IS UNIVERSALLY REQUIRED, WE SHOULD ALL MONITOR GUARD CHANNEL (121.5 OR 243.0) AS A BACKUP, AS THE MIL CURRENTLY DOES. I HOPE IT WORKS BETTER IN THE CIVIL COMMUNITY THAN IT DID WHILE I WAS IN THE MIL, HOWEVER.

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.