Widebody; Low Wing; 4 Turbojet Eng
Flight Crew Last 90 Days 30; Flight Crew Total 15000; Flight Crew Type 3000
Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Other / Unknown
General None Reported / Taken
Company Policy; Aircraft; Procedure
Flight plan is Ops Specs B55 Polar into Canadian Southern; Northern and Arctic Control Areas where true navigation is to be conducted per the Canadian Aviation Authority.  Company procedure is to ignore these true navigation practices and navigate in magnetic reference.  Flight plan published numeric magnetic courses today are up to 21 degrees in deviation with the magnetic courses displayed on the pilot flight display while flying to the active waypoint.  We were unable to comply with SOP requiring a check of flight plan vs airplane course direction to be 'reasonable'.  We were also unable to comply with FAA; Canadian CAA and ICAO recommended practices suggest that 2 degrees of display error is reasonable; we exceed that by over 10 times that value today.Magnetic variation stored in the steering IRS computers appears to be near 20 years in deviation from the current magnetic variation revision as issued by manufacturers Honeywell and Boeing for the HG1050 IRS.  Current aeronautical data as required by FAR 121.97 and Ops Specs A009 does not appear to be onboard the aircraft today.
An air carrier Captain states that his company's procedure to operate in magnetic heading is not in compliance with Canadian and Arctic Control Area rules where true navigation is to be conducted. Magnetic variation stored in the steering Inertial Reference System (IRS) computers appears to be near 20 years old and in deviation from the current magnetic variation.