Narrative:

After takeoff, we switched to london control. London control cleared us to climb to and maintain FL110. Passing through 7800 ft, control called us and told us to maintain FL80. PNF and the relief pilot did not hear the call. I told PNF to verify and I reduced rate of climb. After PNF called london control, we heard a clearance to climb to FL190. Relief pilot said he heard climb to FL90. By this time we saw traffic on TCASII. Passing through 8500 ft, london control called us and told us to maintain FL80. At this point, I started an immediate descent to FL80. By this time, I also had the traffic in sight. Due to aircraft momentum, we reached an altitude of 8700 ft before aircraft started descending. Since I had traffic in sight, I used a firm but not aggressive descent. While descending, we did get a descending RA. Descent rate, I was using, was slightly greater than commanded by TCASII RA. During descent, london control also gave us a left turn to a heading of 330 degrees. After conflicting aircraft cleared us on right side, we were given clearance to climb. Conflict in this situation arose due to poor ATC judgement. Controller should have reclred our flight to a lower altitude sooner. Also, during a situation where a conflict is likely to occur, ATC needs to make it a priority to make sure that aircraft in conflict clearly understand the clearance before talking to other aircraft. There were 2 things in cockpit that also contributed to not resolving the confusion concerning clearance: 1) difficulty in understanding the controller due to his accent, and 2) ATC controller giving a clearance to another aircraft without receiving our readback. The other aircraft I am referring to was not the one in potential conflict with our aircraft. There were no extraneous activities in the cockpit and everyone was looking outside for traffic. My recommendation is to keep good vigilance for traffic under 18000 ft for aircraft crews. My recommendation is for ATC to ensure that in a potential conflict, clearance had been received and understood by the crew. ATC must make it a priority before talking to another aircraft. Supplemental information from acn 560405: we learned the clearance to 19000 ft had been given to another aircraft. The 3 pilots communicated during the event and I felt comfortable in that I had traffic in sight and on TCASII and the first officer was following guidance. The maneuver could have been executed a bit swifter. However, I never felt we were in danger. Perhaps the fact that it was I am in the morning for our bodies, and none of us had slept well, or long, in london, contributed to our slower than normal evasive actions. I might add that the traffic had been given a turn away from us. It was helpful to have a third set of eyes in the cockpit.

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Original NASA ASRS Text

Title: POTENTIAL CONFLICT BTWN A DEP, CLBING B-777 AT 7800 FT CLRED THROUGH THE ALT OF INBOUND ACR TFC AT 9000 FT WHILE ON FREQ WITH LONDON CTL, EGTT, FO.

Narrative: AFTER TKOF, WE SWITCHED TO LONDON CTL. LONDON CTL CLRED US TO CLB TO AND MAINTAIN FL110. PASSING THROUGH 7800 FT, CTL CALLED US AND TOLD US TO MAINTAIN FL80. PNF AND THE RELIEF PLT DID NOT HEAR THE CALL. I TOLD PNF TO VERIFY AND I REDUCED RATE OF CLB. AFTER PNF CALLED LONDON CTL, WE HEARD A CLRNC TO CLB TO FL190. RELIEF PLT SAID HE HEARD CLB TO FL90. BY THIS TIME WE SAW TFC ON TCASII. PASSING THROUGH 8500 FT, LONDON CTL CALLED US AND TOLD US TO MAINTAIN FL80. AT THIS POINT, I STARTED AN IMMEDIATE DSCNT TO FL80. BY THIS TIME, I ALSO HAD THE TFC IN SIGHT. DUE TO ACFT MOMENTUM, WE REACHED AN ALT OF 8700 FT BEFORE ACFT STARTED DSNDING. SINCE I HAD TFC IN SIGHT, I USED A FIRM BUT NOT AGGRESSIVE DSCNT. WHILE DSNDING, WE DID GET A DSNDING RA. DSCNT RATE, I WAS USING, WAS SLIGHTLY GREATER THAN COMMANDED BY TCASII RA. DURING DSCNT, LONDON CTL ALSO GAVE US A L TURN TO A HEADING OF 330 DEGS. AFTER CONFLICTING ACFT CLRED US ON R SIDE, WE WERE GIVEN CLRNC TO CLB. CONFLICT IN THIS SIT AROSE DUE TO POOR ATC JUDGEMENT. CTLR SHOULD HAVE RECLRED OUR FLT TO A LOWER ALT SOONER. ALSO, DURING A SIT WHERE A CONFLICT IS LIKELY TO OCCUR, ATC NEEDS TO MAKE IT A PRIORITY TO MAKE SURE THAT ACFT IN CONFLICT CLRLY UNDERSTAND THE CLRNC BEFORE TALKING TO OTHER ACFT. THERE WERE 2 THINGS IN COCKPIT THAT ALSO CONTRIBUTED TO NOT RESOLVING THE CONFUSION CONCERNING CLRNC: 1) DIFFICULTY IN UNDERSTANDING THE CTLR DUE TO HIS ACCENT, AND 2) ATC CTLR GIVING A CLRNC TO ANOTHER ACFT WITHOUT RECEIVING OUR READBACK. THE OTHER ACFT I AM REFERRING TO WAS NOT THE ONE IN POTENTIAL CONFLICT WITH OUR ACFT. THERE WERE NO EXTRANEOUS ACTIVITIES IN THE COCKPIT AND EVERYONE WAS LOOKING OUTSIDE FOR TFC. MY RECOMMENDATION IS TO KEEP GOOD VIGILANCE FOR TFC UNDER 18000 FT FOR ACFT CREWS. MY RECOMMENDATION IS FOR ATC TO ENSURE THAT IN A POTENTIAL CONFLICT, CLRNC HAD BEEN RECEIVED AND UNDERSTOOD BY THE CREW. ATC MUST MAKE IT A PRIORITY BEFORE TALKING TO ANOTHER ACFT. SUPPLEMENTAL INFO FROM ACN 560405: WE LEARNED THE CLRNC TO 19000 FT HAD BEEN GIVEN TO ANOTHER ACFT. THE 3 PLTS COMMUNICATED DURING THE EVENT AND I FELT COMFORTABLE IN THAT I HAD TFC IN SIGHT AND ON TCASII AND THE FO WAS FOLLOWING GUIDANCE. THE MANEUVER COULD HAVE BEEN EXECUTED A BIT SWIFTER. HOWEVER, I NEVER FELT WE WERE IN DANGER. PERHAPS THE FACT THAT IT WAS I AM IN THE MORNING FOR OUR BODIES, AND NONE OF US HAD SLEPT WELL, OR LONG, IN LONDON, CONTRIBUTED TO OUR SLOWER THAN NORMAL EVASIVE ACTIONS. I MIGHT ADD THAT THE TFC HAD BEEN GIVEN A TURN AWAY FROM US. IT WAS HELPFUL TO HAVE A THIRD SET OF EYES IN THE COCKPIT.

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.