Final answer:
The main difference between RNAV and RNP is that RNP systems include on-board performance monitoring and alerting to ensure aircraft stay within certain navigational accuracy bounds, while RNAV does not have this requirement.
Step-by-step explanation:
The difference between RNAV (Area Navigation) and RNP (Required Navigation Performance) lies in their navigation performance requirements. Both are types of navigation systems that allow an aircraft to fly on any desired flight path within the coverage of ground- or space-based navigation aids, within the limits of the capability of the self-contained systems, or a combination of both.
RNAV is a method of navigation that permits aircraft operation on any desired flight path without the need to fly directly over ground-based navigation aids. It provides a framework for flight within a network of predefined waypoints, defined by coordinates (latitude and longitude).
On the other hand, RNP is a type of RNAV system with on-board performance monitoring and alerting capability. RNP specifies a level of performance required for a specific airspace block. This means the aircraft must be able to maintain a track within a narrower corridor and is typically required to have equipment that can calculate and indicate to the pilot whether the aircraft is within this confined space. This system can assure a certain level of accuracy that RNAV systems might not guarantee.
In summary, while RNAV systems provide the route structure for the aircraft to follow, RNP systems add a layer of performance requirement with real-time alerting that ensures that the aircraft stays within the prescribed navigational accuracy bounds.