ICAO 8168 VOL II PDF

FOREWORD

INTRODUCTION

The Procedures for Air Navigation Services — Aircraft Operations (PANS-OPS) consists of two volumes as follows:

Volume I — Flight Procedures

Volume II — Construction of Visual and Instrument Flight Procedures

The division of the PANS-OPS into the two volumes was accomplished in 1979 as a result of an extensive amendment to the obstacle clearance criteria and the construction of approach-to-land procedures (Amendments 13 and 14). Prior to 1979, all PANS-OPS material was contained in a single document. Table A shows the origin of amendments together with a list of the principal subjects involved and the dates on which the PANS-OPS and the amendments were approved by the Council and when they became applicable.

Volume I — Flight Procedures describes operational procedures recommended for the guidance of flight crew and flight operations personnel. It also outlines the various parameters on which the criteria in Volume II are based so as to illustrate the need to adhere strictly to the published procedures in order to achieve and maintain an acceptable level of safety in operations.

Volume II — Construction of Visual and Instrument Flight Procedures is intended for the guidance of procedures specialists and describes the essential areas and obstacle clearance requirements for the achievement of safe, regular instrument flight operations. It provides the basic guidelines to States, and those operators and organizations producing instrument flight charts that will result in uniform practices at all aerodromes where instrument flight procedures are carried out.

Both volumes present coverage of operational practices that are beyond the scope of Standards and Recommended Practices but with respect to which a measure of international uniformity is desirable. 1.5 The design of procedures in accordance with PANS-OPS criteria assumes normal operations. It is the responsibility of the operator to provide contingency procedures for abnormal and emergency operations.

COMMENTARY ON THE MATERIAL CONTAINED IN VOLUME II

Part I — General

This part contains the general criteria that apply to both conventional as well as RNAV and satellite-based procedures.

Section 1 describes the terminology to assist in the interpretation of terms which are used in the procedures and have a particular technical meaning. In some cases, the terms are defined in other ICAO documents. A list of abbreviations is also provided.

Section 2 provides the general criteria that apply to all phases of flight. In Amendment 12 to the 4th edition, criteria for the procedure identification were included.

Section 3 contains the departure procedures. The specifications concerning instrument departure procedures were first developed by the Obstacle Clearance Panel (OCP) in 1983. The material contained in Volume II was prepared for the use of the procedure design specialists and corresponding material for the use of flight operations personnel including flight crews is contained in Volume I.

In 1990 as a result of the work of an air navigation study group, new material was included concerning specifications, procedures and guidance material relating to the simultaneous operations on parallel or near-parallel runways, including the minimum distances between the runways.

Section 4 contains the general arrival and approach procedures. These procedures were first developed by the Operations Division in 1949 and issued in 1951 and have since been amended a number of times. In 1966, the Obstacle Clearance Panel (OCP) was created to update these procedures for application to all types of aeroplanes taking into account requirements for subsonic multi-jet aeroplanes and technical developments with respect to standard radio navigation aids. As a result of this work, instrument approach procedures criteria were completely revised. The new criteria were incorporated in 1979 in the First Edition of Volume II of PANS-OPS (Amendment 13).

Part II — Conventional procedures

This part describes the procedures for conventional navigation that are specific to the sensor.

Section 1 contains the criteria for precision approaches. The (ILS) precision approaches are more precise than those formerly used for non-precision approach and are based on a scientifically validated method. This has been achieved by means of:

a) a collection of data on aircraft ILS precision approach performance measured during actual instrument meteorological conditions;

b) the development of a mathematical model reflecting the total ILS system performance and the matching of that model against the data collected under a) above;

c) the use of the model to extrapolate ILS precision approach performance in order to establish obstacle assessment surfaces;

d) the development of a model of the missed approach manoeuvre based on aircraft dynamics and matched against observed data, and the use of this model to extrapolate suitable margins for use in conjunction with the approach surfaces described in c); and

e) the combination of the ILS approach and the missed approach mathematical models into an integrated model covering the whole ILS procedure and able to provide an assessment of the risk of collision with obstacles in stated conditions.

A new concept of obstacle clearance for ILS has been incorporated in the new criteria in that the previously used obstacle clearance limit (OCL) concept has been replaced by the new obstacle clearance altitude/height (OCA/H) concept. Three methods of deriving OCA/H values are included which, in turn, involve progressive increases in the degree of sophistication in the treatment and accountability of obstacles. The first two methods employ the use of surfaces and the third uses a collision risk model (CRM) to derive OCA/H. The CRM is designed for use where an evaluation of the specific risk within the obstacle environment is needed to obtain the lowest obstacle clearance values compatible with the required level of safety. A computer programme has been developed for the CRM and is available for use through ICAO.

The precision approach criteria were expanded to MLS category I, II and III in 1994 and GBAS category I in 2004.

Section 2 contains the non-precision approach criteria. The obstacle clearance criteria for non-precision approaches, as amended by Amendment 13, have not been developed to the same degree of sophistication as the precision approach obstacle clearance criteria because the level of safety generally associated with the higher operating minima of non-precision approach procedures is already considered to be acceptable. The procedures, therefore, continue to be based upon available experience and the judgements of experts. They, however, were amended to provide a high degree of flexibility designed to assist the procedures specialist in obtaining the maximum operational advantage compatible with safety.

Based mainly on the experience gained by some States during trial application of the new criteria and as a result of the ICAO PANS-OPS workshop series held from 1980-1984, the criteria were amended twice (Amendments 1 and 4). The changes fall into three general categories as follows:

— editorial amendments to ease the understanding of the criteria

— simplification of calculations which have proved, in practice, to contain a high error potential

— removal of discrepancies which could have made the document difficult to apply and operationally penalizing.

Amendment 1 also aligned the presentation of units with Annex 5, Fourth Edition.

Section 3 contains the criteria for en-route operations for VOR and NDB. These criteria were added to the PANS-OPS in 1996. In 2004 simplified criteria were added to allow for less time consuming effort in large airspaces.

Section 4 contains the criteria for holding procedures. Holding procedures were first developed by the Operations Division in 1949 and issued in 1951. A major revision of these procedures was accomplished in 1965 as a result of the work of the Holding Procedures Panel (HOP). The material developed by the HOP was subsequently divided in 1979 and that part of the material concerning holding procedures was incorporated in PANS-OPS, Volume I and the material covering the construction of holding procedures incorporated in Volume II.

In 1982 as a result of the work of the Obstacle Clearance Panel (OCP) new material and changes to the old material were introduced concerning VOR/DME holding, use of holding procedures by helicopters, buffer areas and entry procedures. In 1986, changes were introduced concerning the VOR TO/FROM indication error zone, the minimum usable DME distance and holding speeds, particularly above 4 250 m (14 000 ft).

Part III — RNAV procedures and satellite based procedures

The first RNAV departure procedures were incorporated in PANS-OPS with the introduction of area navigation (RNAV) departure procedures based on VOR/DME in 1993 arising from the Ninth Meeting of the Obstacle Clearance Panel. Departure procedures for DME/DME, basic GNSS followed in 1998, Procedures for RNP and SBAS departure procedures were introduced in 2001 and 2004 respectively.

Arrival and approach procedures

Similar to the departure procedures, Area navigation (RNAV) criteria for instrument approach procedures were introduced for VOR/DME in 1993. Approach procedures for DME/DME, basic GNSS followed in 1998. Procedures for RNP 0.3 were introduced in 2001. As a result of a CFIT safety initiative, Baro-VNAV criteria based on DME/DME or basic GNSS sensors were included in the document in 2001.

In 2004, GLS Cat I (ILS look alike) criteria based on GBAS receivers were introduced in PANS-OPS. GLS Cat II/III criteria can be expected after the Annex 10 SARPs have been finalized.

The T/Y bar concept was introduced for basic GNSS in 1998 and made applicable for RNAV approach procedures in general in 2004. To facilitate pilots flying a T/Y bar approach, the Terminal Arrival Altitude (TAA) concept was also included.

Holding procedures

Area navigation (RNAV) criteria for holding procedures were included in 1993 arising from the ninth meeting of the Obstacle Clearance Panel. RNP holding procedures were added in 1998. In the 5th edition of PANS-OPS, as a result of the rewrite of PANS-OPS, the VOR/DME criteria were generalized to include DME/DME and basic GNSS as well.

PART IV — Helicopters

Part IV contains the criteria applicable for Helicopter Point-in-space procedures based on a basic GNSS receiver which were introduced in 2004.

STATUS

Procedures for Air Navigation Services (PANS) do not have the same status as Standards and Recommended Practices. While the latter are adopted by Council in pursuance of Article 37 of the Convention and are subject to the full procedure of Article 90, PANS are approved by Council and are recommended to Contracting States for worldwide application.

IMPLEMENTATION

The implementation of procedures is the responsibility of Contracting States; they are applied in actual operations only after, and in so far as States have enforced them. However, with a view to facilitating their processing towards implementation by States, they have been prepared in a language which will permit direct use by operations personnel. While uniform application of the basic procedures in this document is very desirable, latitude is permitted for the development of detailed procedures which may be needed to satisfy local conditions.

PUBLICATION OF DIFFERENCES

The PANS do not carry the status afforded to Standards adopted by the Council as Annexes to the Convention and, therefore, do not come within the obligation imposed by Article 38 of the Convention to notify differences in the event of non-implementation.

However, attention of States is drawn to the provisions of Annex 15 related to the publication in their aeronautical information publications of lists of significant differences between their procedures and the related ICAO procedures.

PROMULGATION OF INFORMATION

The establishment and withdrawal of and changes to facilities, services and procedures affecting aircraft operations provided in accordance with the procedures specified in this document should be notified and take effect in accordance with the provisions of Annex 15.

UNITS OF MEASUREMENT

Units of measurement are given in accordance with the provisions contained in Annex 5. In those cases where the use of an alternative non-SI unit is permitted, the non-SI unit is shown in brackets immediately following the primary SI unit. In all cases the value of the non-SI unit is considered to be operationally equivalent to the primary SI unit in the context in which it is applied. Unless otherwise indicated, the allowable tolerance (accuracy) is indicated by the number of significant figures given and, in this regard, it is to be understood in this document that all zero digits, either to the right or left of the decimal marker, are significant figures.