Narrative:

At position 5005N 2720W at FL300 we received a TA followed shortly afterward with an RA to descend. The RA started with a 1500 FPM descent. Relief pilot disconnected the autoplt and began a descent. The RA quickly increased to 2500 FPM descent which he maintained until reaching an altitude of FL285 at which point the opposite direction aircraft passed directly overhead 400 ft above us. During the event the aural warning said 'traffic; descend' followed by 'increase descent.' we then informed shanwick ATC of an near midair collision and climbed back to our assigned altitude of FL300. I went on break and relief pilot took command of the aircraft. I turned on my computer and camera to download some pictures I had taken during my trip. My other first officer said to me that there was approaching traffic at 12 O'clock and 20 mi out and 1000 ft above us and I might want to take a picture as it passed. As the aircraft approached the 10 mi arc on our TCAS we received a TA and the aircraft showed to be 600 ft above our altitude. We then received the RA and started our descent. When the traffic passed over us it was at an altitude indicated by our TCAS as about FL289. Since I had my camera out and was on a break; I took a picture to identify the aircraft as it passed overhead. From the picture it appeared to be a high wing 4 engine military aircraft.

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Original NASA ASRS Text

Title: A B767 OVER THE ATLANTIC RECEIVED A TCAS RA AND DSNDED TO AVOID CONFLICT. A 4 ENG JET; BELIEVED TO BE MIL; PASSED 400 FT OVERHEAD.

Narrative: AT POS 5005N 2720W AT FL300 WE RECEIVED A TA FOLLOWED SHORTLY AFTERWARD WITH AN RA TO DSND. THE RA STARTED WITH A 1500 FPM DSCNT. RELIEF PLT DISCONNECTED THE AUTOPLT AND BEGAN A DSCNT. THE RA QUICKLY INCREASED TO 2500 FPM DSCNT WHICH HE MAINTAINED UNTIL REACHING AN ALT OF FL285 AT WHICH POINT THE OPPOSITE DIRECTION ACFT PASSED DIRECTLY OVERHEAD 400 FT ABOVE US. DURING THE EVENT THE AURAL WARNING SAID 'TFC; DSND' FOLLOWED BY 'INCREASE DSCNT.' WE THEN INFORMED SHANWICK ATC OF AN NMAC AND CLBED BACK TO OUR ASSIGNED ALT OF FL300. I WENT ON BREAK AND RELIEF PLT TOOK COMMAND OF THE ACFT. I TURNED ON MY COMPUTER AND CAMERA TO DOWNLOAD SOME PICTURES I HAD TAKEN DURING MY TRIP. MY OTHER FO SAID TO ME THAT THERE WAS APCHING TFC AT 12 O'CLOCK AND 20 MI OUT AND 1000 FT ABOVE US AND I MIGHT WANT TO TAKE A PICTURE AS IT PASSED. AS THE ACFT APCHED THE 10 MI ARC ON OUR TCAS WE RECEIVED A TA AND THE ACFT SHOWED TO BE 600 FT ABOVE OUR ALT. WE THEN RECEIVED THE RA AND STARTED OUR DSCNT. WHEN THE TFC PASSED OVER US IT WAS AT AN ALT INDICATED BY OUR TCAS AS ABOUT FL289. SINCE I HAD MY CAMERA OUT AND WAS ON A BREAK; I TOOK A PICTURE TO IDENT THE ACFT AS IT PASSED OVERHEAD. FROM THE PICTURE IT APPEARED TO BE A HIGH WING 4 ENG MIL ACFT.

Data retrieved from NASA's ASRS site as of January 2009 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.