To satisfy the CMNPS navigation systems requirement, aircraft transiting CDA to/from another continent must be at least equipped with:

To satisfy the CMNPS navigation systems requirement, aircraft transiting CDA to/from another continent must be at least equipped with:

• A. dual short range navigation systems
• B. two long range RNAV systems or one navigation system using the inputs from one or more sensor systems, plus one short range navigation system
• C. a single long range RNAV system, plus a short range navigation system
• D. a single long range RNAV system, plus two short range navigation systems

Answer: (B)

Redundancy and diversity of navigation sources are essential for safe intercontinental transit. For long over-ocean routes, you need a navigation setup that can continue to provide accurate position even if one component fails. The requirement is satisfied in two ways: either you have two independent long-range RNAV systems, or you have one long-range RNAV system that uses inputs from multiple sensors (such as an inertial reference system and other sensors) plus a short-range navigation source (like VOR/DME). Two independent long-range RNAV units give you true cross-checks and fault tolerance between two separate references. If one RNAV system encounters a fault, the remaining system can carry the route with the necessary integrity. The alternative configuration—one long-range RNAV with sensor inputs plus a short-range navigation source—also provides redundancy by combining cross-checked RNAV data with sensor-derived navigation and a completely separate short-range reference. This ensures that even if GNSS data or one sensor path is compromised, there is an alternate, independent source to maintain accurate positioning. Choosing only dual short-range navigation or a single long-range RNAV without the additional sensor mix-and-a-short-range reference would leave gaps in integrity and continuity over oceanic areas where ground-based signals are limited or unavailable.

Redundancy and diversity of navigation sources are essential for safe intercontinental transit. For long over-ocean routes, you need a navigation setup that can continue to provide accurate position even if one component fails. The requirement is satisfied in two ways: either you have two independent long-range RNAV systems, or you have one long-range RNAV system that uses inputs from multiple sensors (such as an inertial reference system and other sensors) plus a short-range navigation source (like VOR/DME).

Two independent long-range RNAV units give you true cross-checks and fault tolerance between two separate references. If one RNAV system encounters a fault, the remaining system can carry the route with the necessary integrity. The alternative configuration—one long-range RNAV with sensor inputs plus a short-range navigation source—also provides redundancy by combining cross-checked RNAV data with sensor-derived navigation and a completely separate short-range reference. This ensures that even if GNSS data or one sensor path is compromised, there is an alternate, independent source to maintain accurate positioning.

Choosing only dual short-range navigation or a single long-range RNAV without the additional sensor mix-and-a-short-range reference would leave gaps in integrity and continuity over oceanic areas where ground-based signals are limited or unavailable.