ACR FLC CONFUSION REF CLRNC. HDG DEV.

Narrative

AFTER TKOF FROM HKG ARPT DEP CTL TOLD US TO TURN TO 180 DEG HDG. WE UNDERSTOOD THE TURN TO BE IMMEDIATELY; ATC ADVISED NOT TO TURN UNTIL TATHONG VOR. THE TURN WAS NOT MADE AT THE VOR DUE TO NORMAL DUTIES INSIDE THE COCKPIT BY THE PF; AND THE PNF ALSO LOOKING FOR TFC. DEPS WERE BEING MADE FROM RWY 13 WHILE LNDG WAS BEING MADE TO RWY 31. BOTH PLTS AS WELL AS SO WERE BUSY LOOKING FOR MERGING TFC AT APPROX 8 MI. ATC ADVISED US WE HAD NOT MADE THE TURN (TO 180 DEGS AT THE VOR) AS WE HAD BEEN TOLD. HE THEN GAVE US A HDG TO 190 DEGS. SUPPLEMENTAL INFO FROM ACN 199401: SHORTLY AFTER TKOF AT 3000 FT MSL; PROCEEDING TO TATHONG PT VOR; GIVEN A HDG ASSIGNMENT BY DEP CTL WHICH WAS SOMEWHAT DISTORTED DUE TO OTHER RADIO TFC. INITIALLY STARTED TURN AND CAPT QUESTIONED DEP CTL IF THEY WANTED TURN RIGHT NOW. DEP CTL ADVISED TO MAINTAIN HDG; WHICH I TURNED BACK TO. AFTER PASSING TATHONG PT VOR; DEP CTL DIRECTED US TO TURN R AND STATED; YOU WERE TOLD TO TURN R AFTER PASSING TATHONG PT. WE MISSED THIS XMISSION FROM DEP CTL.