In Oceanic Airspace Operations, which of the following constitutes a Gross Navigational Error?

A Gross Navigational Error in Oceanic Airspace Operations is defined as a significant deviation from the intended flight path or other navigation standards. Each of the criteria provided in the choices highlights a specific aspect of navigational accuracy. When any one of these conditions is met, it indicates a failure to maintain proper navigation standards.

A deviation greater than 15 NM from assigned course is a significant lateral navigation error and can lead to hazardous situations, especially in oceanic airspace where separation from other aircraft is critical. Similarly, an ETA (Estimated Time of Arrival) difference of 2 minutes or more can signify that a deviation has occurred, impacting traffic flow, fuel calculations, and overall flight operations.

Additionally, an altitude deviation of +/- 300 feet is also considerable. Maintaining altitude is essential not only for compliance with air traffic control instructions but also for ensuring safety in relation to other aircraft operating in the same airspace or at differing altitudes.

Combining these criteria indicates a broader understanding that Gross Navigational Errors can result from any one of these issues, and each contributes to a significant risk in flight operations in oceanic airspace. Therefore, the correct answer reflects the holistic nature of identifying gross navigational errors through these various metrics.