Narrative:

The departure of air carrier bb, jun/xx/97, lax-kix, was delayed due to a mechanical problem which resulted in an airplane change. Originally scheduled to depart at XA10Z, the flight eventually departed lax at approximately XC50Z. The flight crew was made up of the captain, first officer, and 2 first officer relief pilots. I was one of the relief pilots. During the preflight phase in the replacement aircraft, air carrier dispatch issued a second flight plan for the flight, 'release 2,' which was different from the original in the oceanic routing, though the initial routing and first several fixes were identical. Flight plan #2 was loaded into the FMC and pre departure clearance was received from ATC via ACARS. The pre departure clearance printout named the first few fixes, then indicated 'as filed' as is normal in the pre departure clearance format. The flight took off at XD03Z. At approximately XD35Z the other relief pilot and I left the cockpit to begin our rest period in the crew rest quarters. Approximately 1 1/2 hours later, as I passed through the cockpit on the way to the lav, the captain told me that on their first oceanic non radar position report, ATC had questioned the route being flown as not what ATC expected. Apparently, ATC had either not received our dispatcher's filing of 'flight plan #2,' or had failed to enter the change into the ATC system. The flight was subsequently cleared on our intended routing (#2), and no aircraft traffic conflicts or deviations occurred. Upon reflection of this occurrence, in addition to the above failure, the format of the pre departure clearance contributed to the error because in its abbreviated format there was a built-in ambiguity that allowed it to fit either flight plan. 2 suggestions to reduce the chance of a recurrence of this type: 1) amplify the format of the pre departure clearance so that at least the first 1 or 2 non radar oceanic fixes of international flts plans be part of the initial routing text. This would be an ATC administrative change. 2) whenever more than 1 flight plan has been issued for a flight, a full route readback of the ATC clearance should be requested by the flight crew, especially when the text of the pre departure clearance would fit more than one of the flight plans.

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Original NASA ASRS Text

Title: AN OCEANIC FLT FROM LAX TO KIX (ZOA AIRSPACE) STARTS OFF ON A WRONG TRACK DUE TO CONFUSION OF CLRNC RECEIVED. FLC HAD RECEIVED 2 PDC'S BUT NOT ENOUGH INFO ABOUT THE CLRNC WAS MADE BTWN THE 2 CLRNCS TO HELP FLC IDENT HOW THE PDC DIFFERED.

Narrative: THE DEP OF ACR BB, JUN/XX/97, LAX-KIX, WAS DELAYED DUE TO A MECHANICAL PROB WHICH RESULTED IN AN AIRPLANE CHANGE. ORIGINALLY SCHEDULED TO DEPART AT XA10Z, THE FLT EVENTUALLY DEPARTED LAX AT APPROX XC50Z. THE FLC WAS MADE UP OF THE CAPT, FO, AND 2 FO RELIEF PLTS. I WAS ONE OF THE RELIEF PLTS. DURING THE PREFLT PHASE IN THE REPLACEMENT ACFT, ACR DISPATCH ISSUED A SECOND FLT PLAN FOR THE FLT, 'RELEASE 2,' WHICH WAS DIFFERENT FROM THE ORIGINAL IN THE OCEANIC ROUTING, THOUGH THE INITIAL ROUTING AND FIRST SEVERAL FIXES WERE IDENTICAL. FLT PLAN #2 WAS LOADED INTO THE FMC AND PDC WAS RECEIVED FROM ATC VIA ACARS. THE PDC PRINTOUT NAMED THE FIRST FEW FIXES, THEN INDICATED 'AS FILED' AS IS NORMAL IN THE PDC FORMAT. THE FLT TOOK OFF AT XD03Z. AT APPROX XD35Z THE OTHER RELIEF PLT AND I LEFT THE COCKPIT TO BEGIN OUR REST PERIOD IN THE CREW REST QUARTERS. APPROX 1 1/2 HRS LATER, AS I PASSED THROUGH THE COCKPIT ON THE WAY TO THE LAV, THE CAPT TOLD ME THAT ON THEIR FIRST OCEANIC NON RADAR POS RPT, ATC HAD QUESTIONED THE RTE BEING FLOWN AS NOT WHAT ATC EXPECTED. APPARENTLY, ATC HAD EITHER NOT RECEIVED OUR DISPATCHER'S FILING OF 'FLT PLAN #2,' OR HAD FAILED TO ENTER THE CHANGE INTO THE ATC SYS. THE FLT WAS SUBSEQUENTLY CLRED ON OUR INTENDED ROUTING (#2), AND NO ACFT TFC CONFLICTS OR DEVS OCCURRED. UPON REFLECTION OF THIS OCCURRENCE, IN ADDITION TO THE ABOVE FAILURE, THE FORMAT OF THE PDC CONTRIBUTED TO THE ERROR BECAUSE IN ITS ABBREVIATED FORMAT THERE WAS A BUILT-IN AMBIGUITY THAT ALLOWED IT TO FIT EITHER FLT PLAN. 2 SUGGESTIONS TO REDUCE THE CHANCE OF A RECURRENCE OF THIS TYPE: 1) AMPLIFY THE FORMAT OF THE PDC SO THAT AT LEAST THE FIRST 1 OR 2 NON RADAR OCEANIC FIXES OF INTL FLTS PLANS BE PART OF THE INITIAL ROUTING TEXT. THIS WOULD BE AN ATC ADMINISTRATIVE CHANGE. 2) WHENEVER MORE THAN 1 FLT PLAN HAS BEEN ISSUED FOR A FLT, A FULL RTE READBACK OF THE ATC CLRNC SHOULD BE REQUESTED BY THE FLC, ESPECIALLY WHEN THE TEXT OF THE PDC WOULD FIT MORE THAN ONE OF THE FLT PLANS.

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.