Narrative:

Accepted handoff on sebound medium large transport at FL330 with control to descend aircraft after clearing FL310 traffic in previous sector. Wanted the control for lower in order to descend aircraft to avoid nebound large transport traffic also at FL330. Aircraft passed with 1 mi at FL330 over rdu VORTAC. The cause I think is linked to recent frequency changes in the sector. Training was occurring the sector handing off sebound FL330. Trainee realized mistake and contacted sector, he did switch aircraft too who had by that time switched aircraft to my frequency. Aircraft never checked on my frequency (pilot says maybe due to malfunction). Nebound aircraft never checked on frequency but reported near miss on 118.82. Contacted several sectors to check for aircraft to no avail. New frequency for my sector 118.92. Frequency for sector 2 positions away 118.82. Old frequency is now assigned to low altitude sector below mine. No briefings were given on new frequency except notices put in a binder to read at your convenience. I am willing to provide additional information by phone. I feel there is a severe lack of judgement in assigning frequency close together in close proximity to one another. Supplemental information from acn 182497: while in cruise at FL330 a message from our ACARS told us to go to 118.92 and call ZDC. Our primary VHF was already tuned to 118.92 so we came up on our secondary VHF and established contact with center. We were told that they were trying to raise us for a number of mins but was unable to and that we had just had a near miss with an large transport flight at our same altitude. We advised center that we had been up on our primary VHF but had heard no transmission from him other than our initial check in. Supplemental information from acn 182501: prior to this about 10 mins, a controller came up on the frequency and told all aircraft to check your radios for a stuck microphone. All 3 pilots on board were monitoring the ATC frequency. Right after the near miss, we called the controller gave us another frequency and told us to climb to FL350. When we questioned the controller he said we were misassigned the frequency and so did medium large transport. Supplemental information from acn 182475: upon questioning the controller he said he had been trying to reach us, but later admitted we were 'misassigned a frequency'. Earlier there had been a stuck microphone on the frequency. Makes a strong case for TCAS!

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Original NASA ASRS Text

Title: NMAC.

Narrative: ACCEPTED HDOF ON SEBOUND MLG AT FL330 WITH CTL TO DSND ACFT AFTER CLRING FL310 TFC IN PREVIOUS SECTOR. WANTED THE CTL FOR LOWER IN ORDER TO DSND ACFT TO AVOID NEBOUND LGT TFC ALSO AT FL330. ACFT PASSED WITH 1 MI AT FL330 OVER RDU VORTAC. THE CAUSE I THINK IS LINKED TO RECENT FREQ CHANGES IN THE SECTOR. TRAINING WAS OCCURRING THE SECTOR HANDING OFF SEBOUND FL330. TRAINEE REALIZED MISTAKE AND CONTACTED SECTOR, HE DID SWITCH ACFT TOO WHO HAD BY THAT TIME SWITCHED ACFT TO MY FREQ. ACFT NEVER CHKED ON MY FREQ (PLT SAYS MAYBE DUE TO MALFUNCTION). NEBOUND ACFT NEVER CHKED ON FREQ BUT RPTED NEAR MISS ON 118.82. CONTACTED SEVERAL SECTORS TO CHK FOR ACFT TO NO AVAIL. NEW FREQ FOR MY SECTOR 118.92. FREQ FOR SECTOR 2 POSITIONS AWAY 118.82. OLD FREQ IS NOW ASSIGNED TO LOW ALT SECTOR BELOW MINE. NO BRIEFINGS WERE GIVEN ON NEW FREQ EXCEPT NOTICES PUT IN A BINDER TO READ AT YOUR CONVENIENCE. I AM WILLING TO PROVIDE ADDITIONAL INFO BY PHONE. I FEEL THERE IS A SEVERE LACK OF JUDGEMENT IN ASSIGNING FREQ CLOSE TOGETHER IN CLOSE PROX TO ONE ANOTHER. SUPPLEMENTAL INFO FROM ACN 182497: WHILE IN CRUISE AT FL330 A MESSAGE FROM OUR ACARS TOLD US TO GO TO 118.92 AND CALL ZDC. OUR PRIMARY VHF WAS ALREADY TUNED TO 118.92 SO WE CAME UP ON OUR SECONDARY VHF AND ESTABLISHED CONTACT WITH CENTER. WE WERE TOLD THAT THEY WERE TRYING TO RAISE US FOR A NUMBER OF MINS BUT WAS UNABLE TO AND THAT WE HAD JUST HAD A NEAR MISS WITH AN LGT FLT AT OUR SAME ALT. WE ADVISED CENTER THAT WE HAD BEEN UP ON OUR PRIMARY VHF BUT HAD HEARD NO XMISSION FROM HIM OTHER THAN OUR INITIAL CHK IN. SUPPLEMENTAL INFO FROM ACN 182501: PRIOR TO THIS ABOUT 10 MINS, A CTLR CAME UP ON THE FREQ AND TOLD ALL ACFT TO CHK YOUR RADIOS FOR A STUCK MICROPHONE. ALL 3 PLTS ON BOARD WERE MONITORING THE ATC FREQ. RIGHT AFTER THE NEAR MISS, WE CALLED THE CTLR GAVE US ANOTHER FREQ AND TOLD US TO CLB TO FL350. WHEN WE QUESTIONED THE CTLR HE SAID WE WERE MISASSIGNED THE FREQ AND SO DID MLG. SUPPLEMENTAL INFO FROM ACN 182475: UPON QUESTIONING THE CTLR HE SAID HE HAD BEEN TRYING TO REACH US, BUT LATER ADMITTED WE WERE 'MISASSIGNED A FREQ'. EARLIER THERE HAD BEEN A STUCK MICROPHONE ON THE FREQ. MAKES A STRONG CASE FOR TCAS!

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.