Air Traffic Management Concept Baseline Definition - The Boeing ...

environment. These standards will be used by the service providers and users to obtain
operational benefits and may be used to varying degrees depending on the operating
environment. The following paragraphs provide further details of the RNP concept and
the examples in paragraph 5.3 illustrate potential or proposed applications of the RNP
MASPS.
5.1.3.1 Required Navigation Performance Concept
RNP is a statement of the navigation performance accuracy, integrity, continuity and
availability necessary for operations within a defined airspace. Boeing’s implementations
of RNP focuses on horizontal applications and specify the accuracy, integrity and
availability of navigation signals and availability of navigation equipment requirements for
a defined airspace (Leslie, R.S. (1996) and Tarlton, T. (1995)).
The RNP concept introduces the containment surfaces to define requirements beyond
accuracy and provide assurance of navigation performance. It defines a region around the
desired airplane path that can be defined, and that the probability that the airplane does not
remain within that region can be bounded. The containment integrity and containment
continuity requirements define the allowable probabilities of certain types of failures for
the navigation system. In particular, the integrity requirement limits the probability of a
malfunction of the navigation system which causes the cross-track component of the total
system error to exceed the cross-track containment limit associated with the current RNP
without annunciation. The continuity requirement limits the probability of the loss of
function, which occurs when the system indicates that it is no longer able to meet the
containment integrity requirement. The containment surface width is typically set at two
times RNP (i.e., the airplane will be located within two times RNP of the FMC estimated
position). The containment surface ties this performance measure to the airspace
environment and has direct operational implications for flight path, separation minima and
obstacle clearance surfaces criteria.
5.1.3.2 Actual Navigation Performance
Actual Navigation Performance (ANP) is the actual estimated navigation system accuracy
with associated integrity for the current FMC position. It is expressed in terms of nautical
miles and represents a radius of a circle centered around the computed position where the
probability of the aircraft being inside the circle is 95%.
The computed accuracy, ANP, is displayed to the crew as ACTUAL (navigation
performance), and annunciation is provided if ANP (ACTUAL) does not comply with the
containment integrity requirement of the current RNP.
5.1.4 Surveillance Performance
5.1.4.1 Required Monitoring Performance
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