Narrative:

On account of higher than forecast headwinds, our flight was behind the estimate for crossing nippi as were preceding flts. We had difficulty reporting our progress because of poor HF propagation and difficulty in tuning the HF. We succeeded in relaying our nippi progress via another aircraft. However, we later learned that that flight had misunderstood our request and relayed only to tokyo and not anchorage center. Thus anchorage center was not aware of our progress. They evidently did not request it from tokyo. We subsequently received instruction from tokyo radio to cross nokka at or before time XA34Z. This was an hour ahead of our original estimate. This caused some confusion as it was obvious we couldn't make this. After several calls on HF it was confirmed that the actual time was to be XB34Z, our original estimate. This nevertheless necessitated an increase of mach number from .80 to .85. As we recalculated we determined that we couldn't make the restr and attempted to call tokyo. On account of propagation and other traffic we failed to get through to tokyo, but as we continued attempts to get through, tokyo radio initiated a call to us with instructions to resume normal speed which we did, taking that to mean that tokyo had resolved any separation difficulties. We acknowledged and specifically requested confirmation that the crossing restr time for nokka was cancelled. Tokyo confirmed this. Several mins later tokyo called again and restored the crossing time requirement. We increased speed, and began recalculating whether we could meet the requirement, but within 5 mins tokyo called clearing us to FL350. On reaching altitude we revised our nokka estimate. We crossed nokka about 20 mins later than the original flight plan estimate. We had maintained our filed mach number throughout the flight except during the period mentioned above when we increased in response to tokyo's instructions. Thus we had no reason to suspect there would be separation problems though we knew we were running behind. Presumably all other flts would be suffering the same headwinds on our route and altitude. However, clearly there must have been separation problems. The HF radio tuned normally during the remainder of the east bound flight. On the return flight to anchorage, the HF again gave tuning problems and was written up at anchorage.

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Original NASA ASRS Text

Title: COMMERCIAL FRT HVT HAD COM PROBLEMS ON EXTENDED OVERWATER FLT. SUSPECTS POSSIBLE LESS THAN STANDARD SEPARATION OCCURRED.

Narrative: ON ACCOUNT OF HIGHER THAN FORECAST HEADWINDS, OUR FLT WAS BEHIND THE ESTIMATE FOR XING NIPPI AS WERE PRECEDING FLTS. WE HAD DIFFICULTY RPTING OUR PROGRESS BECAUSE OF POOR HF PROPAGATION AND DIFFICULTY IN TUNING THE HF. WE SUCCEEDED IN RELAYING OUR NIPPI PROGRESS VIA ANOTHER ACFT. HOWEVER, WE LATER LEARNED THAT THAT FLT HAD MISUNDERSTOOD OUR REQUEST AND RELAYED ONLY TO TOKYO AND NOT ANCHORAGE CENTER. THUS ANCHORAGE CENTER WAS NOT AWARE OF OUR PROGRESS. THEY EVIDENTLY DID NOT REQUEST IT FROM TOKYO. WE SUBSEQUENTLY RECEIVED INSTRUCTION FROM TOKYO RADIO TO CROSS NOKKA AT OR BEFORE TIME XA34Z. THIS WAS AN HR AHEAD OF OUR ORIGINAL ESTIMATE. THIS CAUSED SOME CONFUSION AS IT WAS OBVIOUS WE COULDN'T MAKE THIS. AFTER SEVERAL CALLS ON HF IT WAS CONFIRMED THAT THE ACTUAL TIME WAS TO BE XB34Z, OUR ORIGINAL ESTIMATE. THIS NEVERTHELESS NECESSITATED AN INCREASE OF MACH NUMBER FROM .80 TO .85. AS WE RECALCULATED WE DETERMINED THAT WE COULDN'T MAKE THE RESTR AND ATTEMPTED TO CALL TOKYO. ON ACCOUNT OF PROPAGATION AND OTHER TFC WE FAILED TO GET THROUGH TO TOKYO, BUT AS WE CONTINUED ATTEMPTS TO GET THROUGH, TOKYO RADIO INITIATED A CALL TO US WITH INSTRUCTIONS TO RESUME NORMAL SPD WHICH WE DID, TAKING THAT TO MEAN THAT TOKYO HAD RESOLVED ANY SEPARATION DIFFICULTIES. WE ACKNOWLEDGED AND SPECIFICALLY REQUESTED CONFIRMATION THAT THE XING RESTR TIME FOR NOKKA WAS CANCELLED. TOKYO CONFIRMED THIS. SEVERAL MINS LATER TOKYO CALLED AGAIN AND RESTORED THE XING TIME REQUIREMENT. WE INCREASED SPD, AND BEGAN RECALCULATING WHETHER WE COULD MEET THE REQUIREMENT, BUT WITHIN 5 MINS TOKYO CALLED CLEARING US TO FL350. ON REACHING ALT WE REVISED OUR NOKKA ESTIMATE. WE CROSSED NOKKA ABOUT 20 MINS LATER THAN THE ORIGINAL FLT PLAN ESTIMATE. WE HAD MAINTAINED OUR FILED MACH NUMBER THROUGHOUT THE FLT EXCEPT DURING THE PERIOD MENTIONED ABOVE WHEN WE INCREASED IN RESPONSE TO TOKYO'S INSTRUCTIONS. THUS WE HAD NO REASON TO SUSPECT THERE WOULD BE SEPARATION PROBS THOUGH WE KNEW WE WERE RUNNING BEHIND. PRESUMABLY ALL OTHER FLTS WOULD BE SUFFERING THE SAME HEADWINDS ON OUR ROUTE AND ALT. HOWEVER, CLEARLY THERE MUST HAVE BEEN SEPARATION PROBS. THE HF RADIO TUNED NORMALLY DURING THE REMAINDER OF THE E BOUND FLT. ON THE RETURN FLT TO ANCHORAGE, THE HF AGAIN GAVE TUNING PROBS AND WAS WRITTEN UP AT ANCHORAGE.

Data retrieved from NASA's ASRS site as of August 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.