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AIM

10/12/17

5

−4−55

Arrival Procedures

c. Straight

−in Minimums are shown on the IAP

when the final approach course is within 30 degrees
of the runway alignment (15 degrees for GPS IAPs)
and a normal descent can be made from the IFR
altitude shown on the IAP to the runway surface.
When either the normal rate of descent or the runway
alignment factor of 30 degrees (15 degrees for GPS
IAPs) is exceeded, a straight

−in minimum is not

published and a circling minimum applies. The fact
that a straight

−in minimum is not published does not

preclude pilots from landing straight

−in if they have

the active runway in sight and have sufficient time to
make a normal approach for landing. Under such
conditions and when ATC has cleared them for
landing on that runway, pilots are not expected to
circle even though only circling minimums are
published. If they desire to circle, they should advise
ATC.

d. Side

−Step Maneuver Minimums. Landing

minimums for a side

−step maneuver to the adjacent

runway will normally be higher than the minimums
to the primary runway.

e. Published Approach Minimums.

Approach

minimums are published for different aircraft
categories and consist of a minimum altitude (DA,
DH, MDA) and required visibility. These minimums
are determined by applying the appropriate TERPS
criteria. When a fix is incorporated in a nonprecision
final segment, two sets of minimums may be
published: one for the pilot that is able to identify the
fix, and a second for the pilot that cannot. Two sets of
minimums may also be published when a second
altimeter source is used in the procedure. When a
nonprecision procedure incorporates both a step-
down fix in the final segment and a second altimeter
source, two sets of minimums are published to
account for the stepdown fix and a note addresses
minimums for the second altimeter source.

f. Circling Minimums.

In some busy terminal

areas, ATC may not allow circling and circling
minimums will not be published. Published circling
minimums provide obstacle clearance when pilots
remain within the appropriate area of protection.
Pilots should remain at or above the circling altitude

until the aircraft is continuously in a position from
which a descent to a landing on the intended runway
can be made at a normal rate of descent using normal
maneuvers. Circling may require maneuvers at low
altitude, at low airspeed, and in marginal weather
conditions. Pilots must use sound judgment, have an
indepth knowledge of their capabilities, and fully
understand the aircraft performance to determine the
exact circling maneuver since weather, unique airport
design, and the aircraft position, altitude, and
airspeed must all be considered. The following basic
rules apply:

1.

Maneuver the shortest path to the base or

downwind leg, as appropriate, considering existing
weather conditions. There is no restriction from
passing over the airport or other runways.

2.

It should be recognized that circling

maneuvers may be made while VFR or other flying
is in progress at the airport. Standard left turns or
specific instruction from the controller for maneuver-
ing must be considered when circling to land.

3.

At airports without a control tower, it may be

desirable to fly over the airport to observe wind and
turn indicators and other traffic which may be on the
runway or flying in the vicinity of the airport.

REFERENCE

AC 90

−66A, Recommended Standards Traffic patterns for Aeronautical

Operations at Airports without Operating Control Towers.

4.

The missed approach point (MAP) varies

depending upon the approach flown. For vertically
guided approaches, the MAP is at the decision
altitude/decision height. Non

−vertically guided and

circling procedures share the same MAP and the pilot
determines this MAP by timing from the final
approach fix, by a fix, a NAVAID, or a waypoint.
Circling from a GLS, an ILS without a localizer line
of minima or an RNAV (GPS) approach without an
LNAV line of minima is prohibited.

g. Instrument Approach at a Military Field.

When instrument approaches are conducted by civil
aircraft at military airports, they must be conducted in
accordance with the procedures and minimums
approved by the military agency having jurisdiction
over the airport.

3/29/18

AIM