The Department of Transportation`s
Federal Aviation Administration (FAA)
will develop and implement within the
next year a plan to establish public
use of an innovative air navigation
concept called “Required Navigation
Performance” (RNP) that will
significantly increase capacity and
efficiency in the nation`s airways.

RNP evolves the U.S. National Airspace
System from a ground-based design to one where aircraft can take full advantage of advanced technologies for
precision guidance in the en route
(high-altitude) and terminal (about a
40-mile radius of the airport) areas.
Potential benefits include allowing
more precision approach and departure
paths at airports and keeping aircraft
clear of obstacles and terrain.

Using RNP, flight paths can be
developed that meet operators`
preferred routes and environmental
requirements. Parallel paths also can
be developed that will increase
airspace capacity, both in en route and
terminal operations.

“We intend to be the world`s leader in
realizing the efficiency and safety
advantages this concept can provide,”
said Nicholas Sabatini, FAA associate
administrator for regulation and
certification.

A recent FAA policy statement on RNP
commits the agency to moving forward on
a plan to establish public RNP airspace
and procedures over the United States.
RNP defines the accuracy requirements
to fly in certain airspace. While it
does not specify that an operator carry
a specific type of navigation
equipment, it does require an
automation capability aboard an
aircraft to fly a specific flight
procedure, such as an instrument
approach into a particular airport.

RNP is possible thanks to increasingly
sophisticated levels of automation for
positioning and navigation aboard
aircraft. Aircraft have used onboard
computers for many years under the
concept of area navigation (RNAV):
flying point-to-point without following
a zigzag course dictated by the
location of ground-based navigation
aids. RNP improves that capability,
providing more efficient design and use
of RNAV procedures.

The FAA believes RNP can also provide
substantial safety benefits. For
example, RNP will allow precise
vertical and lateral guidance, similar
to the Instrument Landing System (ILS).
This benefit is possible not only in
the final approach phase but throughout
the entire descent from cruise
altitude, and can be implemented at
runways where no ILS capabilities
exist. 

Because of improved positioning and
navigation capabilities, aircraft will
be able to land at airports in lower
visibility than is allowed today. The
concept will simplify training,
allowing pilots to practice just one
type of instrument approach instead of
the multiple types currently in use.

Alaska Airlines has pioneered the use
of RNP for air carrier operations,
using an FAA-approved RNP/RNAV
instrument approach into Juneau under
lower weather minimums than those
possible with conventional navigation
aids.

Several member states of the
International Civil Aviation
Organization (ICAO) have implemented
RNP in their airspace, and it is used
in some areas of international airspace
as well. The FAA is working with
foreign civil aviation authorities to
harmonize policies and standards so
that RNP can become the “global common
denominator” for air navigation.

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