Aeronautical Information Manual (AIM), page 386

Index   385 -- Page 386 -- 387

c. Other requirements are: radar availability,
nonintersecting final approach courses, precision
approach capability for each runway and, if runways
intersect, controllers must be able to apply visual

separation as well as intersecting runway separation

criteria. Intersecting runways also require minimums

of at least 700 foot ceilings and 2 miles visibility.

Straight in approaches and landings must be made.

d. Whenever simultaneous converging
approaches are in progress, aircraft will be informed
by the controller as soon as feasible after initial
contact or via ATIS. Additionally, the radar controller
will have direct communications capability with the
tower controller where separation responsibility has
not been delegated to the tower.

5-4-18. RNP AR Instrument Approach

These procedures require authorization analogous to
the special authorization required for Category II or
III ILS procedures. Authorization required (AR)
procedures are to be conducted by aircrews meeting
special training requirements in aircraft that meet the
specified performance and functional requirements.

a. Unique characteristics of RNP AR
1. RNP value. Each published line of minima
has an associated RNP value. The indicated value
defines the lateral and vertical performance
requirements. A minimum RNP type is documented
as part of the RNP AR authorization for each operator
and may vary depending on aircraft configuration or
operational procedures (e.g., GPS inoperative, use of
flight director vice autopilot).
2. Curved path procedures. Some RNP
approaches have a curved path, also called a
radius-to-a-fix (RF) leg. Since not all aircraft have
the capability to fly these arcs, pilots are responsible
for knowing if they can conduct an RNP approach

with an arc or not. Aircraft speeds, winds and bank
angles have been taken into consideration in the
development of the procedures.

3. RNP required for extraction or not.

Where required, the missed approach procedure may

use RNP values less than RNP-1. The reliability of

the navigation system has to be very high in order to

conduct these approaches. Operation on these
procedures generally requires redundant equipment,
as no single point of failure can cause loss of both
approach and missed approach navigation.

4. Non-standard speeds or climb gradients.
RNP AR approaches are developed based on standard
approach speeds and a 200 ft/NM climb gradient in
the missed approach. Any exceptions to these
standards will be indicated on the approach
procedure, and the operator should ensure they can
comply with any published restrictions before
conducting the operation.

5. Temperature Limits. For aircraft using
barometric vertical navigation (without temperature
compensation) to conduct the approach, low and
high-temperature limits are identified on the
procedure. Cold temperatures reduce the glidepath
angle while high temperatures increase the glidepath
angle. Aircraft using baro VNAV with temperature
compensation or aircraft using an alternate means for
vertical guidance (e.g., SBAS) may disregard the
temperature restrictions. The charted temperature
limits are evaluated for the final approach segment
only. Regardless of charted temperature limits or
temperature compensation by the FMS, the pilot may
need to manually compensate for cold temperature on
minimum altitudes and the decision altitude.
6. Aircraft size. The achieved minimums may
be dependent on aircraft size. Large aircraft may
require higher minimums due to gear height and/or
wingspan. Approach procedure charts will be
annotated with applicable aircraft size restrictions.

5-4-50 Arrival Procedures

Page 386 of the Aeronautical Information Manual (AIM.pdf)
AIM: Official Guide to Basic Flight Information and ATC Procedures

Index   385 -- Page 386 -- 387