Narrative:

The aircraft was instructed by edmonton center to descend to FL290. On further investigation, the original flight plan was found to have used both an incorrect cardinal altitude and rvsm altitude data when the flight plan was compiled. The actual flight plan reflected FL310 from departure through N6000.00 W08600.00. After this fix it incorrectly showed FL320 through N7500.00 through W08500.00. When the aircraft reached edmonton center, they immediately recognized the aircraft was not on the correct rvsm altitude and issued a descent instruction to the correct FL290 altitude. It was at this time that dispatch became aware of the flight plan error. Because of the assigned FL290 would have necessitated a fuel stop, discussion began with edmonton to enable the continuance of the flight until the aircraft could climb to the appropriate rvsm altitude. When this problem was investigated we found the following: the incorrect altitude issue is a problem when our minimum time tracks zigzags through canadian airspace. Unfortunately this known flaw with the flight planning system is manually corrected by the use of overrides by dispatch support when they message the route into the flight plan computer. Unfortunately the flaw was not found in the time track until edmonton center informed us of the wrong altitude. The current flight planning system is severely challenged when changing from conventional airspace into rvsm airspace and particularly when the flight is starting out on a westerly heading then changing to an easterly heading and then finally back to a westerly heading. The airspace into which this aircraft was flying is some of the most challenging, not only from an ATC perspective, but also from an operational rules perspective and our current flight planning infrastructure is being stretched beyond its fixed fte origins/capabilities. The maintenance of a manual navigation database augmented by data supplied by the time track process is of serious concern. They require too many manual 'user-work-arounds' to many patches with the minimum of automation in terms of quality control checks built into the system to support this type of advanced flight planning.

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Original NASA ASRS Text

Title: B747-400 CREW WAS NOT AT THE CORRECT ALT IN CANADIAN RVSM AIRSPACE. THE COMPANY DID NOT FILE THE CORRECT ALT.

Narrative: THE ACFT WAS INSTRUCTED BY EDMONTON CTR TO DSND TO FL290. ON FURTHER INVESTIGATION, THE ORIGINAL FLT PLAN WAS FOUND TO HAVE USED BOTH AN INCORRECT CARDINAL ALT AND RVSM ALT DATA WHEN THE FLT PLAN WAS COMPILED. THE ACTUAL FLT PLAN REFLECTED FL310 FROM DEP THROUGH N6000.00 W08600.00. AFTER THIS FIX IT INCORRECTLY SHOWED FL320 THROUGH N7500.00 THROUGH W08500.00. WHEN THE ACFT REACHED EDMONTON CTR, THEY IMMEDIATELY RECOGNIZED THE ACFT WAS NOT ON THE CORRECT RVSM ALT AND ISSUED A DSCNT INSTRUCTION TO THE CORRECT FL290 ALT. IT WAS AT THIS TIME THAT DISPATCH BECAME AWARE OF THE FLT PLAN ERROR. BECAUSE OF THE ASSIGNED FL290 WOULD HAVE NECESSITATED A FUEL STOP, DISCUSSION BEGAN WITH EDMONTON TO ENABLE THE CONTINUANCE OF THE FLT UNTIL THE ACFT COULD CLB TO THE APPROPRIATE RVSM ALT. WHEN THIS PROB WAS INVESTIGATED WE FOUND THE FOLLOWING: THE INCORRECT ALT ISSUE IS A PROB WHEN OUR MINIMUM TIME TRACKS ZIGZAGS THROUGH CANADIAN AIRSPACE. UNFORTUNATELY THIS KNOWN FLAW WITH THE FLT PLANNING SYS IS MANUALLY CORRECTED BY THE USE OF OVERRIDES BY DISPATCH SUPPORT WHEN THEY MESSAGE THE RTE INTO THE FLT PLAN COMPUTER. UNFORTUNATELY THE FLAW WAS NOT FOUND IN THE TIME TRACK UNTIL EDMONTON CTR INFORMED US OF THE WRONG ALT. THE CURRENT FLT PLANNING SYS IS SEVERELY CHALLENGED WHEN CHANGING FROM CONVENTIONAL AIRSPACE INTO RVSM AIRSPACE AND PARTICULARLY WHEN THE FLT IS STARTING OUT ON A WESTERLY HEADING THEN CHANGING TO AN EASTERLY HEADING AND THEN FINALLY BACK TO A WESTERLY HEADING. THE AIRSPACE INTO WHICH THIS ACFT WAS FLYING IS SOME OF THE MOST CHALLENGING, NOT ONLY FROM AN ATC PERSPECTIVE, BUT ALSO FROM AN OPERATIONAL RULES PERSPECTIVE AND OUR CURRENT FLT PLANNING INFRASTRUCTURE IS BEING STRETCHED BEYOND ITS FIXED FTE ORIGINS/CAPABILITIES. THE MAINT OF A MANUAL NAV DATABASE AUGMENTED BY DATA SUPPLIED BY THE TIME TRACK PROCESS IS OF SERIOUS CONCERN. THEY REQUIRE TOO MANY MANUAL 'USER-WORK-AROUNDS' TO MANY PATCHES WITH THE MINIMUM OF AUTOMATION IN TERMS OF QUALITY CTL CHKS BUILT INTO THE SYS TO SUPPORT THIS TYPE OF ADVANCED FLT PLANNING.

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.