FLC LOST CONTACT WITH ATC; FAILED TO OPERATE VHF CORRECTLY.

Narrative

THE PROB WAS A LOSS OF COMS WITH ATC. FLYING OVER UNITED KINGDOM; WBOUND ON UL603; WE HAD PASSED POLE HILL VORTAC AND SENT POS RPT. BOTH OF US (CAPT AND FO); WERE WEARING HEADSETS AND MONITORING ATC NORMALLY. 121.5 WAS DIALED IN ON OUR SECOND VHF RADIO; AND WE HAD GOTTEN A GOOD SELCAL CHK WITH STOCKHOLM RADIO JUST PRIOR TO DEP. THE HF WAS STILL DIALED TO THAT FREQ (BOTH RADIOS). WE RECEIVED AN ACARS MESSAGE TO CONTACT SHANWICK. I NOTED THAT WE WERE OVER BEL (BELFAST; UK). I ATTEMPTED CONTACT ON VHF #1 RADIO TO ATC WITH NO RESPONSE. SINCE I HAD SHANWICK CLRNC FREQ FOR OCEANIC READILY AVAILABLE; AND WHILE THE FO WAS LOOKING FOR AN AREA ATC FREQ ON HIS MAP; I CALLED SHANWICK CLRNC (OCEANIC). HE SAID THAT SHANWICK ATC WANTED US AND GAVE US A FREQ. SHANWICK ATC TOLD US THEY HAD BEEN TRYING TO REACH US FOR A 'LONG WHILE.' LATER DURING HDOF TO SHANWICK OCEANIC; THEY SAID A RPT WOULD BE FILED. NO OTHER PROBS OCCURRED. UPON INVESTIGATION; WE FOUND THAT MONITOR SWITCHES FOR 121.5 (VHF #2) HAD BEEN TURNED OFF. I HAD DONE SO; BECAUSE OF INTERFERENCE/CHATTER ON 121.5. THE FO SAID HE DIDN'T REMEMBER FOR SURE; BUT MAY HAVE DONE SO; BECAUSE OF FREQ NOISE. WE HAD A PRINTED COPY OF OUR OCEANIC CLRNC STILL ON THE PRINTER. WHEN TURNED OFF; WE FOUND MESSAGES FROM FLT CTL TO CONTACT ATC. WE HAD NO CHIME TO ALERT US OF THESE MESSAGES. THE FLT ATTENDANTS DID CHIME US DURING THIS TIME. BAD CRM WITH 121.5 RADIOS AND FLT CTL SHOULD SEND MESSAGE DIRECTLY TO ACARS. SUPPLEMENTAL INFO FROM ACN 568224: I BEGAN TO PICK UP NOISE AND STATIC ON 121.5; WHICH I WAS MONITORING. I DESELECTED SO I COULD HEAR MY PRIMARY CTLR. LATER IN THE FLT WE WERE GIVEN NORMAL HDOFS TO LONDON CTL. THE CAPT AND I WERE ENGAGED IN NORMAL CONVERSATION; 'HALF' LISTENING TO OUR RADIOS. APPROX 100 MI FROM ENTERING THE TRACK SYS; WE WERE ABOUT TO REQUEST A CHANGE OF ALT TO MAKE OUR XING. AT THAT TIME WE REALIZED WE HAD NOT HAD A FREQ CHANGE FOR QUITE A WHILE; AND WE SHOULD BE TALKING TO SCOTTISH CTL. WE PULLED A FREQ OFF THE CHART FOR SHANNON CLRNC AND ASKED HIM WHAT FREQ WE SHOULD BE ON. HE GAVE US THE NEW FREQ. AT THAT TIME; I REALIZED I HAD NOT BEEN MONITORING 121.5 SINCE I HAD DESELECTED IT EARLIER. CLRLY WE DID NOT MAINTAIN SITUATIONAL AWARENESS OF OUR FINAL XING AND THE NEED TO CONTACT THAT COUNTRY. WE LOST OUR SITUATIONAL AWARENESS.