Filing a revised flight plan using special routes, which have been issued for aircraft with partial loss of navigation capability.

Note: These special routes are available only if the remaining navigation equipment meets the minimum navigation performance specifications (MNPS) and the requirements in ICAO Annex 6, Part 1 are met using short-range navaids. Request a clearance above or below MNPS airspace.

If one long-range nav system fails after takeoff, but before the aircraft reaches the oceanic boundary, the crew should consider the following options:

Landing at an en route airport that has suitable repair capabilities, or returning to the departure airport.

Filing a revised flight plan using the special routes as just described.

Requesting a clearance above or below MNPS airspace.

If one long-range nav system fails after the aircraft crosses the Oceanic Control Area boundary, the crew may continue to operate the aircraft in accordance with the oceanic clearance received, recognizing that the reliability of the total navigation system is significantly reduced.

If, after entering oceanic airspace and losing one navigation system, the remaining system fails or gives an indication of degraded performance, the flight crew must immediately advise ATC of the loss of navigation equipment.

After assessing the circumstances, consult with ATC to select one of the following optional courses of action:

Continuing to destination.