JEPPESEN GENERAL AIRWAY MANUAL (Issue Date 1 JUL 21)

aircraft under these conditions needs special consideration at aerodromes that are critical due to
obstacles on the missed approach area. This may result in a special procedure being established
with a possible increase in the DA/H or MDA/H.

INITIAL PHASE

The initial phase begins at the MAPt and ends at the start of climb (SOC). This phase requires the
concentrated attention of the pilot on establishing the climb and the changes in aircraft configura-
tion. It is assumed that guidance equipment is not extensively utilized during these manoeuvres,
and for this reason, no turns are specified in this phase.

INTERMEDIATE PHASE

7.3.1 The intermediate phase begins at the SOC. The climb is continued, normally straight
ahead. It extends to the first point where 50 m (164 ft) obstacle clearance is obtained and can be
maintained.
7.3.2 The intermediate missed approach track may be changed by a maximum of 15° from that
of the initial missed approach phase. During this phase, it is assumed that the aircraft begins track
corrections.

FINAL PHASE

The final phase begins at the point where 50 m (164 ft) obstacle clearance is first obtained (for
Category H procedures, 40 m (131 ft)) and can be maintained. It extends to the point where a
new approach, holding or a return to en-route flight is initiated. Turns may be prescribed in this
phase.

TURNING MISSED APPROACH

7.5.1 Turns in a missed approach procedure are only prescribed where terrain or other factors
make a turn necessary.
7.5.2 Where an obstacle is located early in the missed approach procedure, the IAC is annota-
ted “Missed approach turn as soon as operationally practicable to _____ heading“.

Airspeed

7.5.3.1  The protected airspace for turns is based on the speeds for final missed approach (see
Tables II-5-1-1 and II 5-1-2).
7.5.3.2  Where operationally required to avoid obstacles, the IAS as slow as for intermediate
missed approach may be used. In this case, the IAC contains the following note: “Missed
approach turn limited to ____ km/h (kt) IAS maximum”.
7.5.3.3  Pilots shall comply with such annotations on approach charts and to execute the appro-
priate manoeuvres without undue delay.

PBN MISSED APPROACH ATTRIBUTES

7.6.1 A PBN missed approach is a missed approach procedure containing RNAV or RNP seg-
ments.

7.2

7.3

7.4

7.5

7.5.3

7.6

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7.6.2 PBN procedures are promulgated with a PBN requirements box. The box contains the fol-
lowing information:

a. identification of the applicable navigation specification(s) that were used to design the proce-

dure;

b. restrictions on navigation equipment required to fly the procedure (for example GNSS only);

and

c. information related to optional functionality of the applicable navigation specification, such as

the use of RF legs or RNP scalability.

Applicable navigation specifications

The applicable navigation specifications for PBN missed approach segments are:

a. RNP APCH;
b. RNP AR APCH;

c. Advanced RNP;

d. RNP 0.3 (Helicopters);
e. RNAV 1; and

f. RNP 1.

NOTE: For complete details of the applicability of PBN navigation specifications to the missed
approach, see the Performance-based Navigation (PBN) Manual (Doc 9613).
7.6.4 The navigation specifications may be applied on a missed approach route segment basis.
The aircraft and pilot shall be approved to operate on the navigation specification that applies to
the missed approach.
7.6.5 Missed approach procedure information is contained in a navigation database using the
WGS-84 coordinate system. If the navigation database does not contain the missed approach
procedure, the procedure shall not be used.

PBN operational approval

7.6.6.1 Pilots shall verify, before operating on any PBN route or procedure, that they have
approval to operate on the navigation specification used. Where there are additional restrictions,
for example sensor use or optional functionality as discussed in 7.6.2, the pilot shall also verify
that these are complied with.
7.6.6.2 Prior to operating on any PBN procedure, the pilot shall confirm:

a. the operation of all required navigation aids (ground and space-based);
b. the correct functioning of the navigation equipment;

c. the validity of the navigation database; and

d. waypoint and segment data, with reference to the published chart.

7.6.3

7.6.6

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2.1.1.2 These speeds are rounded to the nearest multiple of five for operational reasons. From
the standpoint of operational safety, these speeds are considered to be equivalent to the unroun-
ded originals.

Bank angle/rate of turn

All turns shall be made at a bank angle of 25° or at a rate of 3° per second, whichever requires
the lesser bank.

Allowance for known wind

All procedures depict tracks. The pilot should attempt to maintain the track by making allowance
for known wind by applying corrections both to heading and timing. This should be done during
entry and while flying in the holding pattern.

Start of outbound timing

Outbound timing begins over or abeam the fix, whichever occurs later. If the abeam position
cannot be determined, start timing when the turn to outbound is completed.

Outbound leg length based on a distance measuring equipment (DME)
distance

If the outbound leg length is based on a DME distance, then the outbound leg terminates as soon
as the limiting DME distance is reached.

Limiting radials

2.1.6.1 In the case of holding away from the station (see Figure II-6-1-1 C), where the distance
from the holding fix to the very high frequency omnidirectional radio range/distance measuring
equipment (VOR/DME) station is short, a limiting radial may be specified. A limiting radial may
also be specified where airspace conservation is essential.
2.1.6.2 If the limiting radial is reached before the limiting DME distance, this radial should be fol-
lowed until a turn inbound is initiated. The turn should be initiated at the latest where the limiting
DME distance is reached.

Air traffic control (ATC) notification

If for any reason a pilot is unable to conform to the procedures for normal conditions, ATC should
be advised as early as possible.

HOLD ENTRY

2.2.1 Paragraphs 2.2.3.2 and 2.2.9 related to hold entry represent general guidance. Variations
of the basic procedure for local conditions may be authorized by States after appropriate consul-
tation with the operators concerned.
2.2.2 The entry into the holding pattern shall be according to heading in relation to the three
entry sectors shown in Figure II-6-2-1, recognizing a zone of flexibility of 5° on either side of the
sector boundaries.

2.1.2

2.1.3

2.1.4

2.1.5

2.1.6

2.1.7

2.2

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Restrictions on hold entry

2.2.3.1 For holding on a VOR intersection, the entry track is limited to the radials forming the
intersection.
2.2.3.2 For holding on a VOR/DME fix, the entry track is limited to:

a. the VOR radial;
b. the DME arc (where specified); or

c. the entry radial to a VOR/DME fix at the end of the outbound leg, as published.

Section 1 entry

Sector 1 procedure-parallel entry (see Figure II-6-2-1):

a. at the fix, the aircraft is turned left onto an outbound heading for the appropriate period of

time (see 2.2.9, “Time/distance outbound”); then

b. the aircraft is turned toward the holding side to intercept the inbound track or to return

directly to the fix; and then

c. on second arrival over the holding fix, the aircraft is turned right to follow the holding pattern.

Sector 2 entry

Sector 2 procedure - offset entry (see Figure II-6-2-1):

a. at the fix, the aircraft is turned onto a heading to make good a track making an angle of 30°

from the reciprocal of the inbound track on the holding side; then

b. the aircraft will fly outbound:

1. for the appropriate period of time (see 2.2.9, “Time/distance outbound”), where timing is

specified; or

2. until the appropriate limiting DME distance is reached, where distance is specified. If a

limiting radial is also specified, then the outbound distance is determined either by the
limiting DME distance or the limiting radial, whichever comes first;

c. the aircraft is turned right to intercept the inbound holding track; and

d. on second arrival over the holding-fix, the aircraft is turned right to follow the holding pattern.

Sector 3 entry

Sector 3 procedure - direct entry (see Figure II-6-2-1):
Having reached the fix, the aircraft is turned right to follow the holding pattern.

DME arc entry

To be used where specified. At the fix, the aircraft shall enter the holding pattern in accordance
with either the Sector 1 or Sector 3 entry procedure.

2.2.3

2.2.4

2.2.5

2.2.6

2.2.7

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Special entry procedure for VOR/DME holding

2.2.8.1 Where a special entry procedure is used, the entry radial is clearly depicted.
2.2.8.2 Arrival to a VOR/DME holding pattern may be:

a. along the axis of the inbound track;
b. along a published track; or

c. by radar vectoring, when aircraft shall be established on prescribed protected flight paths.

2.2.8.3 The entry point should be either of the following two options:

a. the holding fix: In this case, the aircraft shall arrive at the entry point by means of:

1. the VOR radial for the inbound leg; or
2. the DME arc defining the holding fix.

b. the fix at the end of the outbound leg, in which case, the aircraft will arrive at the entry point

by means of the VOR radial passing through the fix at the end of the outbound leg.

2.2.8.4  It is also possible to make use of guidance from another radio facility (e.g. non-direc-
tional beacon (NDB)).
2.2.8.5  The following describes the method of arrival at a VOR/DME holding and the corre-
sponding entry procedures, where the entry point is the holding fix.
2.2.8.5.1  For arrival on the VOR radial of the inbound leg, on the same heading as the inbound
track (see Figure II-6-2-2 A) the entry consists of following the holding pattern.
2.2.8.5.2  For arrival on the VOR radial of the inbound leg, on a heading reciprocal to the
inbound track (see Figure II-6-2-2-B):

a. On arrival over the holding fix, the aircraft turns onto the holding side on a track making an

angle of 30° with the reciprocal of the inbound track, until reaching the DME outbound limit-
ing distance.

b. At this point it turns to intercept the inbound track.

c. In the case of a VOR/DME holding entry away from the facility with a limiting radial, if the

aircraft encounters the radial ahead of the DME distance, it shall turn and follow it until
reaching the DME outbound limiting distance, at which point it turns to join the inbound track.

2.2.8.5.3 For arrival on the DME arc defining the holding fix, from the non-holding side (see
Figure II-6-2-2 C):

a. On arrival over the holding fix, the aircraft turns and follows a track parallel to and on the

same heading as the outbound track.

b. When it reaches the DME outbound limiting distance, the aircraft turns to intercept the

inbound track.

2.2.8.5.4 For arrival on the DME arc defining the holding fix, from the holding side (see Figure
II-6-2-2 E):

2.2.8

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a. On arrival over the holding fix, the aircraft turns and follows a track parallel and reciprocal to

the inbound track, until reaching the DME limiting outbound distance. It then turns to inter-
cept the inbound track.

b. If the entry point is the fix at the end of the outbound leg, arrival (or last segment thereof) is

effected along the VOR radial passing through the outbound fix. On arrival over the fix at the
end of the outbound leg, the aircraft turns and follows the holding pattern (see Figure II 6-2-2
F and G).

Time/distance outbound

2.2.9.1 The still air time for flying the outbound entry heading should not exceed:

a. one minute if at or below 4250 m (14000 ft); or
b. one and one-half minutes if above 4250 m (14000 ft).

2.2.9.2 Where DME is available, the length of the outbound leg may be specified in terms of dis-
tance instead of time.

HOLDING

Still air condition

After entering the holding pattern, on the second and subsequent arrivals over the fix, the aircraft
turns to fly an outbound track to position the aircraft for the turn onto the inbound track. It contin-
ues outbound:

a. where timing is specified:

1. for one minute if at or below 4250 m (14000 ft); or
2. for one and one-half minutes if above 4250 m (14000 ft); or

b. where distance is specified until the appropriate limiting DME distance is reached.

Then, the aircraft turns so as to realign itself on the inbound track.

Corrections for wind effect

Allowance should be made in both heading and timing to compensate for the effects of wind to
ensure the inbound track is regained before passing the holding fix inbound. In making these cor-
rections, full use should be made of the indications available from the navaid and estimated or
known wind.

Departing the pattern

When clearance is received specifying the time of departure from the holding point, the pilot
should adjust the pattern within the limits of the established holding procedure in order to leave
the holding point at the time specified.

2.2.9

2.3

2.3.1

2.3.2

2.3.3

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OBSTACLE CLEARANCE

Holding area

The holding area includes the basic holding area and the entry area. The basic holding area is the
airspace required for a holding pattern at a specific level, based on the allowances for aircraft
speed, wind effect, timing errors, holding fix characteristics, etc. The entry area is the airspace
required for the entry procedure.

Buffer area

2.4.2.1 An additional buffer area extends 9.3 km (5.0 NM) beyond the boundary of the holding
area. Significant obstacles in the buffer area are taken into consideration when determining the
minimum holding level.
2.4.2.2 For helicopter holding procedures, the buffer area is 3.7 km (2 NM) wide and only
applies below 1830 m (6000 ft).

Minimum holding level

The minimum permissible holding level (see Figure II-6-2-3) provides a clearance of at least 300
m (984 ft) above obstacles in the holding area, and a clearance which ranges from 300 m (984 ft)
at the edge of the holding area to a minimum of 60 m (197 ft) at the 5.0 NM limit of the buffer
area.

Obstacle clearance over high terrain or in mountainous areas

Over high terrain or in mountainous areas, additional obstacle clearance up to a total of 600 m
(1969 ft) is provided to accommodate the possible effects of turbulence, down drafts and other
meteorological phenomena on the performance of altimeters.

Table IV-1-1 (or II-6-2-1 in PANS-OPS). Holding Speeds - Categories A through E

Levels

Normal conditions

Turbulence conditions

Up to 4250 m (14000 ft) inclusive

425 km/h (230 kt)

520 km/h (280 kt)

315 km/h (170 kt)

Above 4250 m (14000 ft) to 6100
m (20000 ft) inclusive

445 km/h (240 kt)

520 km/h (280 kt)

0.8 Mach,

whichever is less

Above 6100 m (20000 ft ) to
10350 m (34000 ft) inclusive

490 km/h (265 kt)

Above 10350 m (34000 ft)

0.83 Mach

2.4

2.4.1

2.4.2

2.4.3

2.4.4

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Table IV-1-1 (or II-6-2-1 in PANS-OPS). Holding Speeds - Categories A through E (contin-

ued)

Levels

Normal conditions

Turbulence conditions

1. The levels shown represent altitudes or corresponding flight levels depending upon the altime-
ter setting in use.
2. When the holding procedure is followed by the initial segment of an instrument approach pro-
cedure promulgated at a speed higher than 425 km/h (230 kt), the holding should also be pro-
mulgated at this higher speed wherever possible.
3. The speed of 520 km/h (280 kt) (0.8 Mach) reserved for turbulence conditions shall be used
for holding only after prior clearance with ATC, unless the relevant publications indicate that the
holding area can accommodate aircraft flight at these high holding speeds.
4. For holdings limited to CAT A and B aircraft only.
5. Wherever possible, 520 km/h (280 kt) should be used for holding procedures associated with
airway route structures.

Table IV-1-2. PANS-OPS Second Edition Holding Speeds Applicable to Many of the Pres-

ently Published Holdings

Levels

Propeller

aircraft

Jet aircraft

Normal conditions

Turbulence condi-

tions

up to 1850 m inclusive

6000 ft

315 km/h

(170 kt)

390 km/h

(210 kt)

520 km/h

(280 kt) or

0.8 Mach whichever

is less

above 1850 m to 4250 m in-

clusive

6000 ft to 14000 ft

315 km/h

(170 kt)

405 km/h

(220 kt)

above 4250 m

14000 ft

325 km/h

(175 kt)

445 km/h

(240 kt)

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Table IV-1-2. PANS-OPS Second Edition Holding Speeds Applicable to Many of the Pres-

ently Published Holdings (continued)

Levels

Propeller

aircraft

Jet aircraft

Normal conditions

Turbulence condi-

tions

1. The levels tabulated represent altitudes or corresponding flight levels depending upon the
altimeter setting in use.
2. Certain types of propeller aircraft may need to hold at higher speeds.
3. The speed of 520 km/h (280 kt) (0.8 Mach) reserved for turbulence conditions shall be used
for holding only after prior clearance with ATC, unless the relevant publications indicate that the
holding area can accommodate aircraft flying at these high holding speeds.
NOTE: Holdings calculated in accordance with the Second Edition criteria should not be flown at
higher holding speeds as the lateral limits of the holding area are larger when the holding speed
is higher. The obstacle clearance or separation may not be guaranteed when these holdings are
flown at the new higher holding speeds.

Table IV-1-3. Holding Speeds Per U.S. FAA Regulations

Levels

All aircraft

at 6000 ft or below

200 kt

above 6000 ft to and including 14000 ft

230 kt

above 14000 ft

265 kt

1. Holding patterns from 6001 ft to 14000 ft may be restricted to a maximum airspeed of 210 kt.
This nonstandard pattern will be depicted by an icon.
2. Holding patterns at all altitudes may be restricted to a maximum airspeed of 175 kt. This non-
standard pattern will be depicted by an icon.
3. Holding patterns at USAF airfields only - 310 kt maximum, unless otherwise depicted.
4. Holding patterns at U.S. Navy fields only - 230 kt maximum, unless otherwise depicted.

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AIRCRAFT EQUIPPED WITH RNAV SYSTEMS INCLUDING CERTIFIED

RNAV HOLDING FUNCTIONALITY

3.2.1 These systems may be used to carry out RNAV holding, provided that:

a. the aircraft is fitted with serviceable RNAV equipment; and
b. the pilot has a current knowledge of how to operate the equipment to optimize navigation

accuracy.

3.2.2  Holding waypoints and supporting data contained in the navigation database are calcula-
ted and promulgated by the State authority. Holding waypoints may also be input by the operator
or the pilot for some applications (e.g. RNAV 5) when identified in operations approval documen-
tation. Any errors introduced from the navigation database or manual entry will affect the actual
computed position. The pilot should cross-check the waypoint position using VOR/DME fix infor-
mation where this is available.
3.2.3  Some RNAV systems can fly conventional holding patterns without strict compliance with
PANS-OPS, Volume II, assumptions. Before these systems are used operationally, they shall
have demonstrated, to the satisfaction of the appropriate authority, that their commands will con-
tain the aircraft within the basic holding area defined by PANS-OPS, Volume II, for the environ-
mental conditions assumed by those criteria. The pilot shall verify overflight of the stipulated fixes
by means of the reference facility.
3.2.4  Performance-based navigation (PBN) holding may be conducted in specifically designed
holding patterns. These holding patterns utilize the criteria and flight procedure assumptions of
conventional holding with orientations. However, the holding pattern is established on a track to
the holding waypoint. These holding patterns assume that the aircraft is approved for the PBN
navigation specification associated with the holding pattern and is being operated in accordance
with that approval.

CONVENTIONAL HOLDING PATTERNS

Conventional holding patterns may be flown with the assistance of an RNAV system. In this case,
the RNAV system has no other function than to provide guidance for the autopilot or flight direc-
tor. The pilot remains responsible for ensuring that the aircraft complies with the speed, bank
angle, timing and distance assumptions contained in Chapter 2, 2.1 of this section.

PILOT RESPONSIBILITIES

3.4.1 When RNAV equipment is used for non-RNAV holding procedures, the pilot shall verify
inbound track, direction of turn and positional accuracy at the holding fix on each passage of the
fix.
3.4.2 The pilot shall ensure that speeds used to fly the RNAV holding procedures comply with
Tables II-6-2-1 and II-6-2-2.

RNAV HOLDING ENTRIES

Entries into an RNAV holding pattern are the same as for conventional holding unless clearly
specified otherwise.

3.2

3.3

3.4

3.5

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Extracted from ICAO Document 8168, Volume I - Sixth Edition - Procedures for Air Naviga-
tion Services - AIRCRAFT OPERATIONS, Flight Procedures, herein known as PANS-OPS.

GENERAL PRINCIPLES OF PROCEDURE DESIGN

1.1  An instrument flight procedure is a series of predetermined manoeuvres designed to be
flown by referring to the flight instruments. These provide specific protection from obstacles, and
are typically used in the arrival, approach and departures phases of flight.
1.2  There are three main principles that apply to the design of all instrument flight procedures;
they should be safe, as simple as possible and economical in both time and airspace. Safety
requires the use of common sense and operational judgement. Simple procedures are essential
at a time when pilot workload is high and the consequences of error can be fatal. Economical pro-
cedures are increasingly necessary where flight time can have an economic impact and where
airspace is often in short supply.
1.3  The PANS-OPS caters for a wide variety of conditions in each area or segment of an instru-
ment flight procedure. It is important that pilots understand the assumptions used in the design of
procedures and the protections afforded by the procedures so as not to exceed them. The proce-
dure design process involves the following concepts:

a. each instrument flight procedure is characterized by a sequence of segments based on sur-

faces or areas;

b. these areas or segments and their associated obstacle protection are designed in accord-

ance with aircraft category and type of navigation facility; and

c. the areas or segments are assessed to find the highest obstacle within each area or seg-

ment.

The minimum obstacle clearance (MOC) applicable to each area or segment is added to the high-
est obstacle to calculate the minimum obstacle clearance altitudes for each area or segment.
1.4  Obstacle clearance is the primary safety consideration in developing instrument flight proce-
dures, and because of variable factors such as terrain, aircraft characteristics and pilot ability, the
detailed procedures are based on present standard equipment and practices. However, the
obstacle clearance included in the specifications is considered to be the minimum which cannot
be safely reduced.
1.5  Procedures contained in the PANS-OPS assume that all engines are operating. Develop-
ment of contingency procedures is the responsibility of the operator.
1.6  The criteria in the PANS-OPS make use of standard conditions for aircraft characteristics.
However, allowance is made in the criteria to deviate from these standard conditions when spe-
cific airspace or operational requirements apply.
1.7  Where example calculations are used, these assume an elevation of 2000 ft above mean
sea level (MSL) and a temperature of international standard atmosphere (ISA) + 15°C.
1.8  For procedure design purposes where speeds are given in IAS and need to be converted to
true airspeed (TAS), this conversion is achieved on the basis of the ISA where:

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Atmospheric pressure

1013.2hPA

Temperature

+15°C

Temperature lapse rate

2°C / 1000 ft

1.9  All procedures depict tracks or bearings unless otherwise annotated. Pilots should attempt
to therefore maintain the track or bearing by applying corrections to heading for known wind.
1.10  Navigation accuracy requirements in procedure design are normally omnidirectional, in that
winds that have the most adverse effect are considered. Nevertheless, it is expected that pilots
when flying an instrument flight procedure will always correct for the actual or estimated wind,
except when being vectored.
1.11  Different assumed wind speed values are used in procedure design according to the phase
of flight or segment of the procedure. Unless, site-specific, 95 per cent statistical values are avail-
able, the following assumed wind speed values are used:

Phase of flight

Winds used

Departure

30 kt omnidirectional for turns

En-route/initial approach segment

ICAO standard wind of (2 x altitude in feet/
1000) + 47 kt

Holding

ICAO standard wind of (2 x altitude in feet/
1000) + 47 kt

Final and missed approach segments

30 kt for turns

1.12 All published procedures use degrees magnetic.

ADDITIONAL CONSIDERATIONS FOR MOUNTAINOUS AREAS

When procedures are designed for use in mountainous areas, consideration is given to induced
altimeter error and pilot control problems which result when winds of 37 km/h (20 kt) or more
move over such areas. Where these conditions are known to exist, MOC may be increased by as
much as 100 per cent.

BASIC DESIGN CONCEPTS

ACCURACY OF FIXES

General

2.1.1.1 Fixes and points used in designing instrument flight procedures are normally based on
standard navigation systems.
2.1.1.2 Because all navigation facilities and waypoints have accuracy limitations, the geographic
point which is identified is not precise but may be anywhere within an area called the fix tolerance
area which surrounds the plotted location of the facility, waypoint or intersection. Figure A-2-1

1.13

2.1

2.1.1

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illustrates the fix tolerance area formed by the intersection of two radials or tracks from different
navigation facilities.

Fix tolerance factors

2.1.2.1  The dimensions of the fix tolerance area are determined by the system use accuracy of
the navigation aid(s) on which the fix is based, and for conventional navigation aids, on the dis-
tance from the facility.
2.1.2.2  See Table A-2-1 for system use accuracies for conventional navigation aids and Table
A-2-2 for the tolerances on which these values are based.
2.1.2.3  See 2.2.7 for fix tolerances when using performance-based navigation (PBN) systems.

Fix tolerance for other types of navigation systems

2.1.3.1 Surveillance radar. Radar fix tolerances are based on radar mapping accuracies, azi-
muth resolution, flight technical tolerance, controller technical tolerances, and the speed of aircraft
in the terminal area. The fix tolerances are listed below:

a. terminal area surveillance radar (TAR) within 37 km (20 NM): fix tolerance is ±1.6 km (0.8

NM); and

b. en-route surveillance radar (RSR) within 74 km (40 NM): fix tolerance is ±3.2 km (1.7 NM).

2.1.3.2 Distance measuring equipment (DME). Fix tolerance is ±0.46 km (0.25 NM) + 1.25 per
cent of distance to the antenna.
2.1.3.3 75 MHz marker beacon. See Figure A-2-2 to determine the fix tolerance for instrument
landing system (ILS) and “z” markers for use with instrument approach procedures.

Table A-2-1. System use accuracy (2 SD) of facility providing track guidance and facility

not providing track guidance

VOR

ILS

NDB

System use accuracy of facility providing track

±5.2°

±2.4°

±6.9°

System use accuracy of facility NOT providing
track

±4.5°

±1.4°

±6.2°

The VOR values of ±5.2° and ±4.5° may be modified according to the value of a) in Table
A-2-2, resulting from flight tests.

2.1.2

2.1.3

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Table A-2-2. Tolerances on which system use accuracies are based

The values in Table A-2-1 are the result of

a combination, on a root sum square ba-

sis, of the following tolerances:

VOR

ILS

NDB

a) Ground system tolerance

±3.6°

±1°

±3°

b) Airborne receiving system tolerance

±2.7°

±1°

±5.4°

c) Flight technical tolerance

±2.5°

±2°

±3°

Includes beam bends.
Flight technical tolerance is only applied to navigation aids providing track guidance. It is not
applied to fix intersecting navigation aids.

PROTECTED AREAS

Primary and secondary areas

2.2.1.1  For each straight segment of the procedure an area is specified extending either side of
the defined track. Normally the area is symmetrical on both sides of the intended track.
2.2.1.2  In general, this area is subdivided into primary and secondary areas. However, in some
cases, primary areas only are specified. When secondary areas are specified, the outer half of
each side of the area (normally 25 per cent of the total width) is designated as secondary area.
(See Figure A-2-3.)
2.2.1.3  Full obstacle clearance is provided throughout the entire primary area, and in the secon-
dary area, the obstacle clearance is reduced linearly from the full clearance at the inner edge to
zero at the outer edge, as shown in Figure A-2-3.

Calculation of area widths – conventional navigation

2.2.2.1 The actual width of the area is determined by the phase of flight.
2.2.2.2 En-route areas-are constructed differently. See Part II, Section 3, Chapter 1 for details.

Standard arrival routes (STAR) of 46 km or longer (25 NM)

When the length of the arrival route is greater than or equal to 46 km (25 NM), en-route criteria
apply prior to the 46 km (25 NM) distance to the initial approach fix (IAF). The area width decrea-
ses from 46 km (25 NM) with a convergence angle of 30° each side of the axis, until reaching the
width determined by the initial approach criteria.

Arrival routes less than 46 km (25 NM)

When the length of the arrival route is less than 46 km (25 NM), the area width decreases from
the beginning of the arrival route with a convergence angle of 30° each side of the axis, until
reaching the width determined by the initial approach criteria.

2.2

2.2.1

2.2.2

2.2.3

2.2.4

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Initial approach

The initial approach segment has no standard length. The length is that which is sufficient to
permit the altitude change required by the procedure. The width is divided into:

a. a primary area which extends laterally 4.6 km (2.5 NM) on each side of the track; and
b. a secondary area which adds an additional 4.6 km (2.5 NM) on each side of the primary

area.

Intermediate approach

In a straight-in approach, the width of the intermediate approach segment tapers from a maximum
width of ±9.2 km (±5 NM) at the intermediate fix (IF) to its minimum width at the final approach fix
(FAF) (or (FAP)). The segment is divided laterally as follows:

a. a primary area which extends laterally on each side of the track; and
b. a secondary area on each side of the primary area.

PBN fix tolerances and protected areas

2.2.7.1 The obstacle clearance area for PBN is based on the total system error (TSE) which is
dependent upon position estimation error (PEE), path definition error (PDE), display error and
flight technical error (FTE). The PBN protected areas are based upon calculations considering the
following elements.
NOTE: For a description of error as related to performance-based navigation, see the Perform-
ance-based Navigation (PBN) Manual (Doc 9613).

Cross-track tolerance (XTT)

A fix tolerance measured perpendicularly to the nominal track resulting from the airborne and
ground equipment tolerances and the flight technical error (FTE).

Along-track tolerance (ATT)

A fix tolerance measured along the nominal track resulting from the airborne and ground equip-
ment tolerances. See Figure A-2-4 for graphical depiction of XTT and ATT.
2.2.7.1.3 The TSE is then used to define the XTT and ATT values as follows:

a. XTT = TSE
b. ATT = 0.8*TSE

2.2.7.2 For PBN procedures, the width of the area is defined based on the required navigation
performance (RNP) navigation accuracy requirement of the associated navigation specification,
plus a buffer value (see 2.2.7.3).
2.2.7.2.1 Specifically, the semi-width (½ A/W) of the area is:

½ A/W = 1.5 x RNP navigation accuracy requirement + buffer value

2.2.5

2.2.6

2.2.7

2.2.7.1.1

2.2.7.1.2

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2.2.7.2.2 Since the required accuracy figures are constant, there is no splay associated with the
area width of a PBN route or procedure segment.
2.2.7.2.3 Figure A-2-5 shows an example of the area associated with a PBN procedure based
on:

a. RNP 1 navigation specification; and
b. STAR route between 56 km (30 NM) and 28 km (15 NM) from the aerodrome reference point

(ARP).

This results in a ½ A/W of (1.5 x 1) + 1 = 2.5 NM.
2.2.7.2.4 The ½ A/W value calculated in this way is used in all PBN procedures except RNP AR
procedures and final approach segments (FAS) of RNP APCH procedures based on the use of
satellite-based augmentation system (SBAS) (SBAS approach procedure with vertical guidance
(APV)-I, SBAS CAT I and SBAS non-precision approach (NPA)). The buffer value is based on air-
craft characteristics (speed, manoeuvrability, etc.) and the phase of flight and is used to address
blunder errors beyond a 3 standard deviation value. Buffer values do not apply to the FAS of
approach procedures based on the use of SBAS.
2.2.7.3 Buffer values. Buffer values for phase of flight are presented in Table A-2-3.
NOTE: Helicopter only procedures use different buffer values.

Table A-2-3. Buffer values (BV) for phase of flight

Phase of

flights

En-route

Terminal

FAS

Missed ap-

proach

Application Standard instrument

departures (SIDs) and
STARs greater than
or equal to 56 km (30
NM) from departure or
destination ARP

STARS, initial and inter-
mediate segments less
than 56 km (30 NM) from
ARP and SIDs and missed
approach segments less
than 56 km (30 NM) from
ARP but more than 28 km
(15 NM) from ARP

Missed approach
segments and
SIDs up to 28 km
(15 NM) from the
ARP

BV for

CAT A - E

3704 m

(2.0 NM)

1852 m

(1.0 NM)

926 m

(0.5 NM)

926 m

(0.5 NM)

2.2.7.4 XTT and ½ A/W values for phases of flight. For PBN operations, values of XTT are
assigned based on the phase of flight and the applicable navigation specifications to that phase of
flight. Tables A-2-4 and A-2-7 present the XTT values for the phase of flight and applicable navi-
gation specifications. A blank (—) cell in the table indicates the navigation specification is not
applicable to that phase of flight. Tables A-2-5 and A-2-8 depict the ½ A/W values for the various
flight phases and applicable navigation specifications.

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NOTE: The identification of applicable navigation specifications for a given phase of flight can be
found in Doc 9613, Table II-A-1-1.

Table A-2-4. Navigation specification and phase of flight XTT fix tolerances (NM)

Phase of flight

Navigation

specifica-

tion

En-route/SID/

STAR

(>30 NM

from ARP)

STAR/IF/IAF/SID/

missed approach

(<30 NM from ARP)

FAF

MAPt

Misse

d ap-

pro-

ach

(<15

ARP)

SID

(<15

ARP)

RNAV 1/
RNAV 2

2.00

1.00

—

1.00

RNP 2

2.00

—

RNP 1

1.00

(SID/STAR)

1.00

—

1.00

RNP APCH

—

1.00

0.3

/0.0216

0.3

/0.021
6

1.00

—

A-RNP

2.00 or 1.00

1.00

0.3

1.00

RNP 0.3

0.30

—

0.30

RNAV 2 is intended for use outside of the terminal control area (TMA), and RNAV 1 for TMA
applications.
RNP APCH Section A (LNAV/VNAV) only.
RNP APCH Section B (LP/LPV) only.
A-RNP permits a range of scalable navigation accuracy requirements, as detailed in Doc 9613.
However, PANS-OPS, Volume II, contains only criteria for 1 NM accuracy values, so for consis-
tency this is the only value presented here.
Intended for helicopter operations only.

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Table A-2-5. Navigation specification and phase of flight ½ A/W (NM)

Phase of flight

Navigation

specifica-

tion

En-route/SID/

STAR

(>30 NM from

ARP)

STAR/IF/IAF/SID/

missed approach

(<30 NM from ARP)

FAF

MAPt

Missed

approach

(<15 NM

ARP)

SID

(<15 NM

ARP)

RNAV 1/
RNAV 2

5.00

2.50

—

2.00

RNP 2

5.00

—

RNP 1

3.50

(SID/STAR)

2.50

—

2.00

RNP APCH

—

2.50 (IF/IAF/missed ap-

proach only)

1.45

/N/

0.95

N/A

2.00

—

A-RNP

5.00 or 3.50

2.50

1.45

0.95

2.00

RNP 0.3

1.45

1.15

—

0.80

RNAV 2 is intended for use outside of the TMA, and RNAV 1 for TMA applications.
RNP APCH Section A (LNAV/VNAV) only.
RNP APCH Section B (LP/LPV) only.
A-RNP permits a range of scalable navigation accuracy requirements, as detailed in Doc 9613.
However, PANS-OPS, Volume II, contains only criteria for 1 NM accuracy values, so for consis-
tency this is the only value presented here.
Intended for helicopter operations only.

2.2.7.4.1  RNAV 1 criteria are used for SIDs and STARs that can be supported by either global
navigation satellite system (GNSS) or DME/DME infrastructure.
2.2.7.4.2  RNP 1 criteria are used for SIDs and STARs using GNSS as the primary navigation
sensor.
2.2.7.4.3  RNP APCH criteria are divided into two sections. Section A criteria, which are used for
RNAV (GNSS) instrument approach procedures, are applied only within 56 km (30 NM) of the
destination ARP. Outside this distance either RNAV 1 or RNP 1 criteria are used unless otherwise
specified. For Section A criteria, the XTT at both the FAF and MAPt is 556 m (0.3 NM). Addition-
ally, Section A ½ A/W criteria taper from ±2685 m (1.45 NM) at the FAF to ±1759 m (0.95 NM) at
the MAPt.
2.2.7.4.4  Criteria associated with RNP APCH Section B are applicable to approach procedures
based on the use of SBAS. Section B criteria capture the benefits of angular guidance on the
FAS. The XTT value at the FAF and MAPt is 40.0 m. The final approach ½ A/W values at the FAF
are dependent on the length of the FAS.

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2.2.7.4.5 Area width for CAT H. Because of the flight characteristics of helicopters there are
slight reductions in the ½ A/W values for arrival, approach and departure phases of flight when
certain navigation specifications are used to design the procedure. The reduction is in the buffer
values used to calculate the ½ A/W:

a. for en-route and SIDs/STARs >56 km (30 NM) from the ARP, the buffer value is 1852 m (1.0

NM);

b. in the TMA the buffer value is 1296 m (0.7 NM); and

c. for the final segment the buffer value is 648 m (0.35 NM).

2.2.7.4.6 Tables A-2-6 and A-2-9 identify ½ A/W values for CAT H that are different from those
depicted in Table A-2-5.

Table A-2-6. Navigation specification and phase of flight ½ A/W (NM) (CAT H)

Phase of flight

Naviga-

tion spec-

ification

En-route/SID/

STAR

(>30 NM from

ARP)

STAR/IF/IAF/SID/

missed approach

(<30 NM from ARP)

FAF

MAPt Missed ap-

proach

(<15 NM

ARP)

SID

(<15 NM

ARP)

RNAV 1/
RNAV 2

4.00

2.20

—

1.85

RNP 1

2.50

(SID/STAR)

2.20

—

1.85

RNP
APCH

—

2.20 (IF/IAF/missed ap-

proach only)

1.15

0.80

N/A

1.85

—

RNAV 2 is intended for use outside of the TMA and RNAV 1 for TMA applications.
RNP APCH Section A (LNAV/VNAV) only.
RNP APCH Section B (LP/LPV) only.

Table A-2-7. Navigation specification and phase of flight XTT fix tolerances (m)

Phase of flight

Naviga-

tion spec-

ification

En-route/SID/

STAR

(>56 km from

ARP)

STAR/IF/IAF/SID/

missed approach

(<56 km from ARP)

FAF

MAPt

Missed

approach

(<28 km

ARP)

SID

(<28 km

ARP)

RNAV 1/
RNAV 2

3704

1852

—

1852

RNP 2

3704

—

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Table A-2-7. Navigation specification and phase of flight XTT fix tolerances (m) (continued)

Phase of flight

Naviga-

tion spec-

ification

En-route/SID/

STAR

(>56 km from

ARP)

STAR/IF/IAF/SID/

missed approach

(<56 km from ARP)

FAF

MAPt

Missed

approach

(<28 km

ARP)

SID

(<28 km

ARP)

RNP 1

1852

(SID/STAR)

1852

—

1852

RNP
APCH

—

1852

556

/40

556

/40

1852

—

A-RNP

3704 or 1852

1852

556

1852

RNP 0.3

556

—

556

RNAV 2 is intended for use outside of the TMA, and RNAV 1 for TMA applications.
RNP APCH Section A (LNAV/VNAV) only.
RNP APCH Section B (LP/LPV) only.
A-RNP permits a range of scalable navigation accuracy requirements, as detailed in Doc 9613.
However, PANS-OPS, Volume II, contains only criteria for 1 NM accuracy values so for consis-
tency this is the only value presented here.
Intended for helicopter operations only.

Table A-2-8. Navigation specification and phase of flight ½ A/W (m)

Phase of flight

Naviga-

tion spec-

ification

En-route/SID/

STAR

(>56 NM from

ARP)

STAR/IF/IAF/SID/

missed approach

(<56 NM from ARP)

FAF

MAPt

Missed ap-

proach

(<28 NM

ARP)

SID

(<28 NM

ARP)

RNAV 1/
RNAV 2

9260

4630

—

3704

RNP 2

9260

—

RNP 1

6482

(SID/STAR)

4630

—

3704

RNP
APCH

—

4630 (IF/IAF/missed

approach only)

2685

1759

N/A

3704

—

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Table A-2-8. Navigation specification and phase of flight ½ A/W (m) (continued)

Phase of flight

Naviga-

tion spec-

ification

En-route/SID/

STAR

(>56 NM from

ARP)

STAR/IF/IAF/SID/

missed approach

(<56 NM from ARP)

FAF

MAPt

Missed ap-

proach

(<28 NM

ARP)

SID

(<28 NM

ARP)

A-RNP

9260 or 6482

4630

2685

1759

3704

RNP 0.3

2685

2130

—

1482

RNAV 2 is intended for use outside of the TMA, and RNAV 1 for TMA applications.
RNP APCH Section A (LNAV/VNAV) only.
RNP APCH Section B (LP/LPV) only.
A-RNP permits a range of scalable navigation accuracy requirements, as detailed in Doc 9613.
However, PANS-OPS, Volume II, contains only criteria for 1 NM accuracy values so for consis-
tency this is the only value presented here.
Intended for helicopter operations only.

Table A-2-9. Navigation specification and phase of flight ½ A/W (m) (CAT H)

Phase of flight

Naviga-

tion spec-

ification

En-route/SID/

STAR

(>56 km from

ARP)

STAR/IF/IAF/SID/

missed approach

(<56 km from ARP)

FAF

MAPt

Missed ap-

proach

(<28 km

ARP)

SID

(<28 km

ARP)

RNAV 1/
RNAV 2

7400

4074

—

3426

RNP 1

4630

(SID/STAR)

4074

—

3426

RNP
APCH

—

4074 (IF/IAF/missed ap-

proach only)

2130

N/A

1482

N/A

3426

—

RNAV 2 is intended for use outside of the TMA, and RNAV 1 for TMA applications.
RNP APCH Section A (LNAV/VNAV) only.
RNP APCH Section B (LP/LPV) only.

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TURN AREA CONSTRUCTION

General

A turning point may be specified in any of three ways. (See Part II, Section 1, 1.5 for a descrip-
tion.)

Turn parameters

The turn area is defined by a number of parameters, these include:

a. altitude;
b. indicated airspeed (IAS);

c. wind;

d. bank angle (

);

e. flight technical tolerances;

f. fix tolerance (see section 1 of this appendix); and

g. rate of turn (R) in degrees/second.

Calculation of the protection area for turns

2.3.3.1 As with any turning manoeuvre, speed is a controlling factor in determining the aircraft
track during the turn.

Inner boundary

The inner boundary caters for the slowest aircraft. It starts at the earliest fix tolerance of the turn-
ing point and splays outward at an angle of 15° relative to the nominal track.

Outer boundary

The outer boundary of the turning area is based on the highest speed of the category for which
the procedure is authorized.
2.3.3.1.3  The protection area starts at a point which is determined by the latest fix tolerance and
discussion of FTE.
2.3.3.1.4  There are two methods for constructing the curving portion of the outer boundary.
2.3.3.1.4.1  Wind spirals. In the wind spiral method, the area is based on a radius of turn (r) cal-
culated for a specific value of TAS and bank angle. The outer boundary of the tum area is con-
structed using a spiral derived from the still air radius (r). The resultant spiral is created from
applying wind effect for the time taken to change heading by the specified amount for the turn.
2.3.3.1.4.2  Bounding circles. As an alternative to the wind spiral, a simplified method can be
used in which circles are drawn to bound the turning area. Unlike the wind spiral method, the wind
effect used here is always that of a course change of 90°. The area so constructed is larger and
therefore, more conservative.
2.3.3.2  Where no track guidance is provided during a turn specified by the procedure, the total
width of the area is considered primary area.

2.3

2.3.1

2.3.2

2.3.3

2.3.3.1.1

2.3.3.1.2

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PERFORMANCE-BASED NAVIGATION – PATH TERMINATORS

General

2.4.1.1  All data used by a navigation system for PBN that is certified for terminal operations are
held in a navigation database. These databases are derived from data that is coded in accord-
ance with the aviation industry standard: ARINC 424 — Navigation System Database Specifica-
tion, or an equivalent industry standard.
2.4.1.2  In order to achieve the translation of the textual description of a procedure, and the
routes depicted on the charts into a code suitable for navigation systems, the aviation industry
has developed the “path and termination” concept for terminal procedures.
2.4.1.3  The path terminators are described in detail in PANS-OPS, Volume II, Part III, Section 2,
Chapter 5. They are used to define specific ground tracks on the assumption that aircraft
approved to fly PBN procedures have the capability to maintain consistent tracks based upon the
use of appropriate ARINC 424 path terminators or their equivalent.
2.4.1.4  Path terminators define each segment of a PBN route from take-off until the en-route
segment is joined, and from the point where the aircraft leaves the en-route segment until the end
of the PBN procedure(s).
2.4.1.5  Path terminators are not used to construct en-route segments or other routes outside
terminal airspace.
2.4.1.6  Many aircraft are equipped with systems that are only capable of using a subset of the
available ARINC 424 path terminators.

Path and terminator combinations

2.4.2.1 Each segment of the procedure is identified by a two-letter code which denotes the path
and terminator for the segment. These codes are shown in Table A-2-10.

Table A-2-10. Path and terminator codes

Path

Code

Terminator

Code

Course to

Altitude

Direct track

Fix

Fix to

Intercept

Hold

Manual termination

Initial

Constant radius

Track between

Heading to

2.4

2.4.1

2.4.2

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JEPPESEN GENERAL AIRWAY MANUAL (Issue Date 1 JUL 21) - page 33