Descent to the PT completion altitude from the PT fix
altitude (when one has been published or assigned by ATC)
must not begin until crossing over the PT fix or abeam and
proceeding outbound. Some procedures contain a note in
the chart profile view that says “Maintain (altitude) or above
until established outbound for procedure turn. ” Newer
procedures simply depict an “at or above” altitude at the PT
fix without a chart note. Both are there to ensure required
obstacle clearance is provided in the procedure turn
entry zone. Absence of a chart note or specified minimum
altitude adjacent to the PT fix is an indication that descent
to the procedure turn altitude can commence immediately
upon crossing over the PT fix, regardless of the direction
of flight. This is because the minimum altitudes in the PT
entry zone and the PT maneuvering zone are the same.
A holding pattern-in-lieu-of procedure turn may be
specified for course reversal in some procedures. In
such cases, the holding pattern is established over an
intermediate fix or a FAF. The holding pattern distance or
time specified in the profile view must be observed. For a
hold-in-lieu-of PT, the holding pattern direction must be
flown as depicted and the specified leg length/timing must
not be exceeded. Maximum holding airspeed limitations as
set forth for all holding patterns apply. The holding pattern
maneuver is completed when the aircraft is established on
the inbound course after executing the appropriate entry.
If cleared for the approach prior to returning to the holding
fix and the aircraft is at the prescribed altitude, additional
circuits of the holding pattern are not necessary nor
expected by ATC. If pilots elect to make additional circuits
to lose excessive altitude or to become better established
on course, it is their responsibility to so advise ATC upon
receipt of their approach clearance. Refer to the AIM section
5-4-9 for additional information on holding procedures.
Initial Approach Segment
The purposes of the initial approach segment are to provide
a method for aligning the aircraft with the intermediate
or final approach segment and to permit descent during
the alignment. This is accomplished by using a DME arc,
a course reversal, such as a procedure turn or holding
pattern, or by following a terminal route that intersects
the final approach course. The initial approach segment
begins at an IAF and usually ends where it joins the
intermediate approach segment or at an IF. The letters IAF
on an approach chart indicate the location of an IAF and
more than one may be available. Course, distance, and
minimum altitudes are also provided for initial approach
segments. A given procedure may have several initial
approach segments. When more than one exists, each joins
a common intermediate segment, although not necessarily
at the same location.
Many RNAV approaches make use of a dual-purpose IF/
IAF associated with a hold-in-lieu-of PT (HILO) anchored at
the Intermediate Fix. The HILO forms the Initial Approach
Segment when course reversal is required.
When the PT is required, it is only necessary to enter the
holding pattern to reverse course. The dual purpose fix
functions as an IAF in that case. Once the aircraft has
entered the hold and is returning to the fix on the inbound
course, the dual-purpose fix becomes an IF, marking the
beginning of the intermediate segment.
ATC may provide a vector to an IF at an angle of 90 degrees
or less and specify “Cleared Straight-in (type) Approach” .
In those cases, the radar vector is providing the initial
approach segment and the pilot should not fly the PT
without a clearance from ATC.
Occasionally, a chart may depict an IAF, although there is
no initial approach segment for the procedure. This usually
occurs at a point located within the en route structure
where the intermediate segment begins. In this situation,
the IAF signals the beginning of the intermediate segment.
Intermediate Approach Segment
The intermediate segment is designed primarily to position
the aircraft for the final descent to the airport. Like the feeder
route and initial approach segment, the chart depiction of
the intermediate segment provides course, distance, and
minimum altitude information.
The intermediate segment, normally aligned within 30° of
the final approach course, begins at the IF, or intermediate
point, and ends at the beginning of the final approach
segment. In some cases, an IF is not shown on an approach
chart. In this situation, the intermediate segment begins at
a point where you are proceeding inbound to the FAF, are
properly aligned with the final approach course, and are
located within the prescribed distance prior to the FAF. An
instrument approach that incorporates a procedure turn
is the most common example of an approach that may
not have a charted IF. The intermediate segment in this
example begins when you intercept the inbound course
after completing the procedure turn. [Figure 4-34]
Final Approach Segment
The final approach segment for an approach with vertical
guidance or a precision approach begins where the
glideslope/glidepath intercepts the minimum glideslope/
glidepath intercept altitude shown on the approach
chart. If ATC authorizes a lower intercept altitude, the final
approach segment begins upon glideslope/glidepath
Feeder route
FAF
IF
IAF
RunwayInitial Intermediate Final Missed
approach
Re-enter
En route phase
IAF
IF
FAF Obstacle
Flightpath
Map
500 feet
1,000 feet 1,000 feet250 feet
Project view
Profile view
Plan view
Figure 4-28. Approach segments and obstacle clearance.
interception at that altitude. For a non-precision approach,
the final approach segment begins either at a designated
FAF, which is depicted as a cross on the profile view, or at
the point where the aircraft is established inbound on the
final approach course. When a FAF is not designated, such
as on an approach that incorporates an on-airport VOR
or NDB, this point is typically where the procedure turn
intersects the final approach course inbound. This point
is referred to as the final approach point (FAP). The final
approach segment ends at either the designated MAP or
upon landing.
There are three types of procedures based on the final
approach course guidance:
• Precision approach (PA)—an instrument approach
based on a navigation system that provides course
and glidepath deviation information meeting
precision standards of ICAO Annex 10. For example,
PAR, ILS, and GLS are precision approaches.
• Approach with vertical guidance (APV) —an
instrument approach based on a navigation system
that is not required to meet the precision approach
standards of ICAO Annex 10, but provides course
and glidepath deviation information. For example,
Baro-VNAV, LDA with glidepath, LNAV/VNAV and LPV
are APV approaches.
• Non-precision approach (NPA)—an instrument
approach based on a navigation system that
provides course deviation information but no
glidepath deviation information. For example, VOR,
TACAN, LNAV, NDB, LOC, and ASR approaches are
examples of NPA procedures.
Missed Approach Segment
The missed approach segment begins at the MAP and ends
at a point or fix where an initial or en route segment begins.
The actual location of the MAP depends upon the type of
approach you are flying. For example, during a precision
or an APV approach, the MAP occurs at the DA or DH on
the glideslope/glidepath. For non-precision approaches,
the MAP is either a fix, NAVAID, or after a specified period
of time has elapsed after crossing the FAF.
Approach Clearance
According to FAA Order 7110.65, ATC clearances authorizing
instrument approaches are issued on the basis that if visual
contact with the ground is made before the approach is
completed, the entire approach procedure is followed
unless the pilot receives approval for a contact approach, is
cleared for a visual approach, or cancels the IFR flight plan.
Approach clearances are issued based on known traffic.
The receipt of an approach clearance does not relieve the
pilot of his or her responsibility to comply with applicable
Figure 4-29. Feeder routes.
Figure 4-30. Terminal routes.
NM
NM 4 NM4 NM
feet
feet
1,000
feet
Initial segment
Intermediate
segment 500
feet
feet
VORTAC
NM
NM
4 NM
4 NM
Length
The intermediate segment may NOT be less than
5 NM nor more than 15 NM in length, measured
along the arc. The OPTIMUM length is 10 NM.
A distance greater than 10 NM should not be used
unless an operational requirement justifies the
greater distance.
Width
The total width of an arc intermediate segment is 6
NM on each side of the arc. For obstacle clearance
purposes, this width is divided into a primary and a
secondary area. The primary area extends 4 NM
laterally on each side of the arc segment. The
secondary areas extend 2 NM laterally on each side
of the primary area.
Required Obstacle Clearance (ROC)
The ROC is 1,000 feet for the primary initial segment.
The secondary area ROC starts at the primary ROC
surface tapering to zero at the edges of the secondary
area in both initial and intermediate areas. In the
primary area of the intermediate segment, the ROC is
500 feet.
Figure 4-31. DME arc obstruction clearance.
parts of the CFRs and notations on instrument approach
charts, which impose on the pilot the responsibility to
comply with or act on an instruction, such as “procedure
not authorized at night. ” The name of the approach, as
published, is used to identify the approach. Approach name
items within parentheses are not included in approach
clearance phraseology.
Vectors To Final Approach Course
The approach gate is an imaginary point used within ATC
as a basis for vectoring aircraft to the final approach course.
The gate is established along the final approach course one
mile from the FAF on the side away from the airport and is
no closer than 5 NM from the landing threshold. Controllers
are also required to ensure the assigned altitude conforms
to the following:
• For a precision approach, at an altitude not above
the glideslope/glidepath or below the minimum
glideslope/glidepath intercept altitude specified
on the approach procedure chart.
• For a non-precision approach, at an altitude that
allows descent in accordance with the published
procedure.
Further, controllers must assign headings that
intercept the final approach course no closer than
the following table:
A typical vector to the final approach course and associated
approach clearance is as follows:
“ …four miles from LIMAA, turn right heading three four
zero, maintain two thousand until established on the
localizer, cleared ILS runway three six approach. ”
Other clearance formats may be used to fit individual
circumstances, but the controller should always assign an
altitude to maintain until the aircraft is established on a
segment of a published route or IAP . The altitude assigned
must guarantee IFR obstruction clearance from the point at
which the approach clearance is issued until the aircraft is
established on a published route. 14 CFR Part 91, § 91.175
(j) prohibits a pilot from making a procedure turn when
vectored to a FAF or course, when conducting a timed
approach, or when the procedure specifies “NO PT. ”
When vectoring aircraft to the final approach course,
controllers are required to ensure the intercept is at least
Reversal fix may
be specified
Complete in “remain
within” distance
The 45°/180° procedure turn
Base turnThe 80°/260° procedure turn
Racetrack procedure
Specified time or depicted fix
1 minute
Reversal fix may
be specified
Complete in “remain
within” distance
1 min 15 sec-Cat C,D&E
Figure 4-32. Course reversal methods.
2 NM outside the approach gate. Exceptions include the
following situations, but do not apply to RNAV aircraft
being vectored for a GPS or RNAV approach:
• When the reported ceiling is at least 500 feet above
the MVA/MIA and the visibility is at least 3 SM (may
be a pilot report (PIREP) if no weather is reported for
the airport), aircraft may be vectored to intercept
the final approach course closer than 2 NM outside
the approach gate but no closer than the approach
gate.
• If specifically requested by the pilot, aircraft may
be vectored to intercept the final approach course
inside the approach gate but no closer than the FAF.
Nonradar Environment
In the absence of radar vectors, an instrument approach
begins at an IAF. An aircraft that has been cleared to
a holding fix that, prior to reaching that fix, is issued a
clearance for an approach, but not issued a revised routing,
such as, “proceed direct to… ” is expected to proceed via the
last assigned route, a feeder route if one is published on
the approach chart, and then to commence the approach
as published. If, by following the route of flight to the
holding fix, the aircraft would overfly an IAF or the fix
associated with the beginning of a feeder route to be used,
the aircraft is expected to commence the approach using
the published feeder route to the IAF or from the IAF as
appropriate. The aircraft would not be expected to overfly
and return to the IAF or feeder route.
For aircraft operating on unpublished routes, an altitude
is assigned to maintain until the aircraft is established
on a segment of a published route or IAP . (Example:
“Maintain 2,000 until established on the final approach
course outbound, cleared VOR/DME runway 12. ”) The FAA
definition of established on course requires the aircraft
to be established on the route centerline. Generally, the
controller assigns an altitude compatible with glideslope/
glidepath intercept prior to being cleared for the approach.
Types of Approaches
In the NAS, there are approximately 1,105 VOR stations, 916
NDB stations, and 1,194 ILS installations, including 25 LOC-
type directional aids (LDAs), 11 simplified directional facilities
(SDFs), and 235 LOC only facilities. As time progresses, it is
the intent of the FAA to reduce navigational dependence on
VOR, NDB, and other ground-based NAVAIDs and, instead,
to increase the use of satellite-based navigation.
To expedite the use of RNAV procedures for all instrument
pilots, the FAA has begun an aggressive schedule to
develop RNAV procedures. As of 2010, the number of
RNAV/ GPS approaches published in the NAS numbered
Obstacle
Obstacle
Entry zone
Maneuvering zone
Procedure turn completion altitude
Altitude restricted until completing
departing turn fix outbound
6,000
6,900
7,700
1,000 feet
1,000 feet
Figure 4-33. Procedure turn obstacle clearance.
10,212 - with additional procedures published every revision
cycle. While it had originally been the plan of the FAA to
begin decommissioning VORs, NDBs, and other ground-
based NAVAIDs, the overall strategy has been changed to
incorporate a majority dependence on augmented satellite
navigation while maintaining a satisfactory backup system.
This backup system includes retaining all CAT II and III ILS
facilities and close to one-half of the existing VOR network.
Each approach is provided obstacle clearance based on the
FAA Order 8260.3 TERPS design criteria as appropriate for
the surrounding terrain, obstacles, and NAVAID availability.
Final approach obstacle clearance is different for every
type of approach but is guaranteed from the start of the
final approach segment to the runway (not below the MDA
for non-precision approaches) or MAP , whichever occurs
last within the final approach area. It is dependent upon
the pilot to maintain an appropriate flight path within
the boundaries of the final approach area and maintain
obstacle clearance.
There are numerous types of instrument approaches
available for use in the NAS including RNAV (GPS), ILS, MLS,
LOC, VOR, NDB, SDF, and radar approaches. Each approach
has separate and individual design criteria, equipment
requirements, and system capabilities.
Visual and Contact Approaches
To expedite traffic, ATC may clear pilots for a visual
approach in lieu of the published approach procedure if
Initial approach segment
Feeder route
En route fix
IAF
FAF Beginning of intermediate segment
Figure 4-34. Approach without a designated IF.
flight conditions permit. Requesting a contact approach
may be advantageous since it requires less time than
the published IAP and provides separation from IFR and
special visual flight rules (SVFR) traffic. A contact or visual
approach may be used in lieu of conducting a SIAP , and
both allow the flight to continue as an IFR flight to landing
while increasing the efficiency of the arrival.
Visual Approaches
When it is operationally beneficial, ATC may authorize
pilots to conduct a visual approach to the airport in
lieu of the published IAP . A pilot, or the controller,
can initiate a visual approach. Before issuing a visual
approach clearance, ATC must verify that the pilot
has the airport, or a preceding aircraft that they are to
follow, in sight. Once the pilot reports the airport, or
aircraft, in sight, the pilot is responsible to maintain safe
altitudes and separation from other aircraft. If the pilot
reports the airport in sight but does not see the aircraft
they are assigned to follow, ATC may still issue the
visual approach clearance but the controller maintains
responsibility for aircraft separation (including wake
turbulence separation). Once pilots report the aircraft
in sight, they assume the responsibilities for their own
separation and wake turbulence avoidance.
A visual approach is an ATC authorization for an aircraft
on an IFR flight plan to proceed visually to the airport of
intended landing; it is not an IAP . Also, there is no missed
approach segment. An aircraft unable to complete a visual
approach must be handled as any other go-around and
appropriate separation must be provided. A vector for a
visual approach may be initiated by ATC if the reported
ceiling at the airport of intended landing is at least 500 feet
above the MVA/MIA and the visibility is 3 SM or greater. At
airports without weather reporting service, there must be
reasonable assurance through area weather reports and
PIREPs that descent and approach to the airport can be
made visually, and the pilot must be informed that weather
information is not available.
The visual approach clearance is issued to expedite the flow
of traffic to an airport. It is authorized when the ceiling is
reported or expected to be at least 1,000 feet AGL and the
visibility is at least 3 SM. Pilots must remain clear of the
clouds at all times while conducting a visual approach. At
an airport with a control tower, pilots may be cleared to fly a
visual approach to one runway while others are conducting
VFR or IFR approaches to another parallel, intersecting, or
converging runway. Also, when radar service is provided,
it is automatically terminated when the controller advises
pilots to change to the tower or advisory frequency. While
conducting a visual approach, the pilot is responsible for
providing safe obstacle clearance.
Contact Approaches
If conditions permit, pilots can request a contact approach,
which is then authorized by the controller. A contact
approach cannot be initiated by ATC. This procedure may
be used instead of the published procedure to expedite
arrival, as long as the airport has a SIAP the reported ground
visibility is at least 1 SM, and pilots are able to remain clear
of clouds with at least one statute mile flight visibility
throughout the approach. Some advantages of a contact
approach are that it usually requires less time than the
published instrument procedure, it allows pilots to retain
the IFR clearance, and provides separation from IFR and
SVFR traffic. On the other hand, obstruction clearances and
VFR traffic avoidance becomes the pilot’s responsibility.
Unless otherwise restricted, the pilot may find it necessary
to descend, climb, or fly a circuitous route to the airport to
maintain cloud clearance or terrain/ obstruction clearance.
The main differences between a visual approach and
a contact approach are: a pilot must request a contact
approach, while a visual approach may be assigned by ATC
or requested by the pilot; and a contact approach may be
approved with one mile visibility if the flight can remain
clear of clouds, while a visual approach requires the pilot
to have the airport in sight, or a preceding aircraft to be
followed, and the ceiling must be at least 1,000 feet AGL
with at least 3 SM visibility.
Charted Visual Flight Procedures
A charted visual flight procedure (CVFP) may be established
at some airports with control towers for environmental or
noise considerations, as well as when necessary for the
safety and efficiency of air traffic operations. Designed
primarily for turbojet aircraft, CVFPs depict prominent
landmarks, courses, and recommended altitudes to specific
runways. When pilots are flying the Roaring Fork Visual
RWY 15, shown in Figure 4-35, mountains, rivers, and towns
provide guidance to Aspen, Colorado’s Sardy Field instead
of VORs, NDBs, and DME fixes.
Pilots must have a charted visual landmark or a preceding
aircraft in sight, and weather must be at or above the
published minimums before ATC will issue a CVFP
clearance. ATC will clear pilots for a CVFP if the reported
ceiling at the airport of intended landing is at least 500
feet above the MVA/MIA, and the visibility is 3 SM or more,
unless higher minimums are published for the particular
CVFP . When accepting a clearance to follow traffic, the pilot
is responsible for maintaining a safe altitude, approach
interval and wake turbulence separation from other aircraft
Pilots must advise ATC if unable at any point to continue
a charted visual approach or if the pilot loses sight of the
preceding aircraft.
RNAV Approaches
Because of the complications with database coding,
naming conventions were changed in January 2001 to
accommodate all approaches using RNAV equipment into
one classification which is RNAV. This classification includes
both ground- based and satellite dependent systems.
Eventually all approaches that use some type of RNAV will
reflect RNAV in the approach title.
This changeover is being made to reflect two shifts in
instrument approach technology. The first shift is the
use of the RNP concept outlined in Chapter 1, Departure
Procedures, in which a single performance standard
concept is being implemented for departure/approach
procedure design. Through the use of RNP , the underlying
system of navigation may not be required, provided the
aircraft can maintain the appropriate RNP standard. The
second shift is advanced avionics systems, such as FMS,
used by most airlines, needed a new navigation standard by
which RNAV could be fully integrated into the instrument
approach system.
An FMS uses multi-sensor navigation inputs to produce
a composite position. Essentially, the FMS navigation
function automatically blends or selects position sensors to
compute aircraft position. Instrument approach charts and
RNAV databases needed to change to reflect these issues.
A complete discussion of airborne navigation databases
is included in Chapter 6, Airborne Navigation Databases.
Due to the multi- faceted nature of RNAV, new approach
criteria have been developed to accommodate the design
of RNAV instrument approaches. This includes criteria for
terminal arrival areas (TAAs), RNAV basic approach criteria,
and specific final approach criteria for different types of
RNAV approaches.
Terminal Arrival Areas
The Terminal Arrival Area (TAA) provides a transition
from the en route structure to the terminal environment
with little required pilot/air traffic control interface for
aircraft equipped with Area Navigation (RNAV) systems.
TAAs provide minimum altitudes with standard obstacle
clearance when operating within the TAA boundaries.
TAAs are primarily used on RNAV approaches but may be
used on an ILS approach when RNAV is the sole means for
navigation to the IF; however, they are not normally used
in areas of heavy concentration of air traffic . [Figure 4-36]
The basic design of the RNAV procedure underlying the
TAA is normally the “T” design (also called the “Basic T”).
The “T” design incorporates two IAFs plus a dual purpose
IF/IAF that functions as both an intermediate fix and an
initial approach fix. The T configuration continues from the
IF/IAF to the FAF and then to the MAP . The two base leg
IAFs are typically aligned in a straight-line perpendicular to
the intermediate course connecting at the IF/IAF. A Hold-
in-Lieu-of Procedure Turn (HILO) is anchored at the IF/IAF
and depicted on U.S. Government publications using the
“hold−in−lieu−of−PT” holding pattern symbol. When the
HILO is necessary for course alignment and/or descent,
the dual purpose IF/IAF serves as an IAF during the entry
into the pattern. Following entry into the HILO pattern
and when flying a route or sector labeled “NoPT, ” the dual-
purpose fix serves as an IF, marking the beginning of the
Intermediate Segment.
The standard TAA based on the “T” design consists of
three areas defined by the IAF legs and the intermediate
segment course beginning at the IF/IAF. These areas are
called the straight−in, left−base, and right−base areas.
[Figure 4-36] TAA area lateral boundaries are identified
by magnetic courses TO the IF/IAF. The straight−in area
can be further divided into pie−shaped sectors with the
boundaries identified by magnetic courses TO the IF/ IAF,
and may contain step-down sections defined by arcs based
on RNAV distances from the IF/IAF.
Entry from the terminal area onto the procedure is normally
accomplished via a no procedure turn (NoPT) routing or via
a course reversal maneuver. The published procedure will
be annotated “NoPT” to indicate when the course reversal
is not authorized when flying within a particular TAA sector
[Figures 4-36 and 4-37]. Otherwise, the pilot is expected
to execute the course reversal under the provisions of 14
CFR § 91.175. The pilot may elect to use the course reversal
pattern when it is not required by the procedure, but must
receive clearance from air traffic control before beginning
the procedure.
ATC should not clear an aircraft to the left base leg or right
base leg IAF within a TAA at an intercept angle exceeding 90
degrees. Pilots must not execute the HILO course reversal
when the sector or procedure segment is labeled “NoPT. ”
ATC may clear aircraft direct to the fix labeled IF/IAF if
the course to the IF/IAF is within the straight-in sector
labeled “NoPT” and the intercept angle does not exceed
90 degrees. Pilots are expected to proceed direct to the IF/
IAF and accomplish a straight-in approach. Do not execute
HILO course reversal. Pilots are also expected to fly the
straight−in approach when ATC provides radar vectors and
monitoring to the IF/IAF and issues a“straight-in” approach
clearance; otherwise, the pilot is expected to execute the
HILO course reversal. (See AIM Paragraph 5−4−6, Approach
Clearance)
On rare occasions, ATC may clear the aircraft for an
approach at the airport without specifying the approach
procedure by name or by a specific approach (e.g., “cleared
RNAV Runway 34 approach”) without specifying a particular
IAF. In either case, the pilot should proceed direct to the IAF
or to the IF/IAF associated with the sector that the aircraft
will enter the TAA and join the approach course from that
point and if required by that sector (i.e., sector is not labeled
“NoPT), complete the HILO course reversal.
Note: If approaching with a TO bearing that is on a sector
boundary, the pilot is expected to proceed in accordance
with a “NoPT” routing unless otherwise instructed by ATC.
Altitudes published within the TAA replace the MSA alti
tude. However, unlike MSA altitudes the TAA altitudes are
operationally usable altitudes. These altitudes provide at
least 1,000 feet of obstacle clearance, and more in moun
tainous areas. It is important that the pilot knows which
area of the TAA that the aircraft will enter in order to com
ply with the minimum altitude requirements. The pilot
can determine which area of the TAA the aircraft will enter
by determining the magnetic bearing of the aircraft TO
the fix labeled IF/IAF. The bearing should then be com
pared to the published lateral boundary bearings that
define the TAA areas. Do not use magnetic bearing to the
right-base or left-base IAFs to determine position.
An ATC clearance direct to an IAF or to the IF/IAF with
out an approach clearance does not authorize a pilot to
descend to a lower TAA altitude. If a pilot desires a low
Figure 4-35. Charted visual flight procedures (CVFP).