TPM Review – SEP

TPM Review – SEP

61ST ANNUAL CONFERENCE, 23-27 May 2022

WP No. 64

TPM Review – SEP

Presented by TOC



Over the past few years, TOC came to the conclusion that the TPM was in need of a significant overhaul in order to ensure consistency throughout the manual and with ICAO. Every year, several slight changes are made to individual policies, but there is a need to look at the entire TPM in a holistic way.


1.1. In an effort to ensure the Technical Professional Manual (TPM) is up to date and harmonized with ICAO documentation the manual is being edited section by section. This paper seeks to provide edits to the Separation (SEP) section of the TPM.


2.1. The SEP section of the TPM features several policies in need of review. Some of them need relatively minor edits while several of them are outdated and need major overhaul or removal.

2.2. SEP 7.1 – Use of 1000 ft Vertical Separation above FL 290.

2.2.1. The 1st paragraph of the policy opens with a section regarding RVSM. While most of the world adheres to Flight Levels measured in feet, there are a few states that provide service in Metric measurement. Seeing as there is already implementation worldwide, the need for implementation procedures are not needed. This paragraph is proposed for deletion:

IFATCA TPM (2019), SEP 7.1 – Use of 1000 ft Vertical Separation above FL 290

The reduction of vertical separation above FL 290 should not be implemented in any Region until the necessary procedures, staff and equipment are available to safely and expeditiously handle aircraft in the airspace experiencing the reduction and also in systems responsible for transition areas to airspace not affected by a reduction.


2.2.2. In the 2nd paragraph within the policy one segment needs clerical changes including the addition of the word “shall” and capitalization:

IFATCA TPM (2019), SEP 7.1 – Use of 1000 ft Vertical Separation above FL 290

Only aircraft capable of meeting the Minimum Aircraft Systems Performance Specifications (MASPS) upon which reduced separation is dependent shall be permitted to operate in areas where reduced vertical separation is in effect.


2.2.3. Regarding the 3rd paragraph, this segment remains strong and valid and only needs minor editing:

IFATCA TPM (2019), SEP 7.1 – Use of 1000 ft Vertical Separation above FL 290

Exceptionally, State aircraft may should only be accepted when appropriate procedures have been evaluated and validated, and controllers are trained in the operation of a mixed-traffic environment. If non MASPS (e.g. military) State aircraft are required to operate in RVSM airspace then, in order to preserve system safety, their number should be kept to the absolute minimum.


2.2.4. In the 4th paragraph, the existing policy specifies equipage; such listings can become out of date which is the case here. However, the concept remains strong and valid as a step toward safety, but the wording must be changed to look toward future changes. The revised policy would state:

IFATCA TPM (2019), SEP 7.1 – Use of 1000 ft Vertical Separation above FL 290

IFATCA is opposed to any derogation, mitigation or exemptions such as for non-RVSM equipped State aircraft and aircraft not meeting ACAS II (TCAS version 7.0) requirement adding complexity or unduly increasing controller workload, except in coordinated contingency emergency situations.


2.2.5. Regarding the 5th paragraph, at the time of the policy’s creation the information was correct, however since then references to Flight Level Orientation Scheme (FLOS) have been removed from Annex 2. Seeing as this portion of the policy is no longer current it is proposed for deletion:

IFATCA TPM (2019), SEP 7.1 – Use of 1000 ft Vertical Separation above FL 290

Failing a clear operational advantage for either the single alternate or the double alternate Flight Level Orientation Scheme (FLOS), IFATCA proposes that RVSM trials utilise the single alternate FLOS in order to achieve the global application in accordance with ICAO Annex 2. In order to validate the results during this trial period, enhancements on a sub-regional level may become necessary through adequate Flight Level Allocation Schemes (FLAS).


2.2.6. Regarding the 6th paragraph, due to worldwide implementation of RVSM stratum the phase for trial testing the infrastructure should be complete. Therefore, it is suggested that this paragraph is deleted:

IFATCA TPM (2019), SEP 7.1 – Use of 1000 ft Vertical Separation above FL 290

IFATCA urges all states concerned to ensure that the appropriate infra-structure will be in place prior to the commencement of these trials, this involves staff, equipment, training, airspace and route structure, including the transition areas. All factors must be verified and validated through simulations prior to implementation.


2.2.7. Regarding the final paragraph of the policy, the proposed investigation into lateral offset has led to the creation of ICAO Circular 331 “Implementation of Strategic Lateral Offset Procedures.” This document was created combining several work groups to develop offset values and procedures for the application of strategic lateral offset. PANS- ATM has also been updated to include policy regarding Strategic Lateral Offset Procedure (SLOP).


Note 1.— SLOP are approved procedures that allow aircraft to fly on a parallel track to the right of the centre line relative to the direction of flight to mitigate the lateral overlap probability due to increased navigation accuracy and wake turbulence encounters. Unless specified in the separation standard, an aircraft’s use of these procedures does not affect the application of prescribed separation standards.

 Note 2.— Annex 2,, requires authorization for the application of strategic lateral offsets from the appropriate ATS authority responsible for the airspace concerned.

PANS ATM 16th Edition

 As a result of the matter being covered by ICAO policy and the existing policy being outdated it is proposed for deletion:

IFATCA TPM (2019), SEP 7.1 – Use of 1000 ft Vertical Separation above FL 290

IFATCA endorses the investigation of the concept regarding the use of lateral offset in Oceanic RVSM airspace.


2.3. SEP 7.3 – Formation Flights within Controlled Airspace.

2.3.1. In the first section of the policy, the prescribed phraseology does not appear in PANS ATM 16th Edition 8th Amendment. Therefore, the use of ‘formation’ should not be prescribed by IFATCA alone and would be better handled by local orders. As a result, is suggested that this section of policy is removed from the TPM:

IFATCA TPM (2019), SEP 7.3 – Formation Flights within Controlled Airspace

The word ‘formation’ shall be used in the radio callsign of a formation flight at least once, on first contact with each ATC frequency.


2.3.2. Regarding the second part of the policy, the details for what constitutes a formation flight and who is responsible for separation thereof are laid out in ICAO Annex 2.

b) separation between aircraft in the flight shall be the responsibility of the flight leader and the pilots-in-command of the other aircraft in the flight and shall include periods of transition when aircraft are manoeuvring to attain their own separation within the formation and during join-up and breakaway; and

c) a distance not exceeding 1 km (0.5 NM) laterally and longitudinally and 30 m (100 ft) vertically from the flight leader shall be maintained by each aircraft.

Annex 2 – 3.1.8 Formation flights

Since these items are covered within an existing ICAO document it is proposed that this policy is deleted:

IFATCA TPM (2019), SEP 7.3 – Formation Flights within Controlled Airspace

If conditions are such that the aircraft of the formation are unable to maintain separation within controlled airspace from each other, the formation leader will inform the controlling authority. The formation leader is responsible for separation between aircraft comprising the formation until standard separation has been achieved.


2.4. SEP 7.4 – Airborne Separation Assistance Systems (ASAS) and Cockpit Display of Traffic Information (CDTI).

2.4.1. The concept of the policy remains strong and valid there are some alterations that need to be made for harmonization and clarity.

2.4.2. The first paragraph does bring up an issue that could be stated with less ambiguity. The goal is to ensure the which party has the onus for separation is obvious to all parties involved; whether that is the pilot or the controller. The current policy revised wording would read:

IFATCA TPM (2019), SEP 7.4 – Airborne Separation Assistance Systems (ASAS) and Cockpit Display of Traffic Information (CDTI)

Where ASAS-applications procedures are implemented, which involve a change of responsibility for separation, this shall be clearly stated and be made known to all airspace users.  a clear and unambiguous statement for separation responsibility is required.


2.4.3. The third paragraph would be amended to be more forward thinking for future implementations:

IFATCA TPM (2019), SEP 7.4 – Airborne Separation Assistance Systems (ASAS) and Cockpit Display of Traffic Information (CDTI)

The publication of MOPS (Minimum Operational Performance Specifications) for CDTIs by ICAO, or another internationally recognized organisation, is urgently required shall be developed prior to any implementation of ASAS.


2.4.4. The final paragraph edit is minor with changing the phrase “need to” to shall for harmonization:

IFATCA TPM (2019), SEP 7.4 – Airborne Separation Assistance Systems (ASAS) and Cockpit Display of Traffic Information (CDTI)

New ICAO phraseology shall be developed before ASAS applications are deployed. Identification issues need to shall be resolved prior to implementation of ASAS applications. Procedures shall be in place to ascertain that any action taken by a crew in the use of ASAS applications will not generate additional conflicts.


2.5. SEP 7.5 – Controller Intervention Buffer.

2.5.1. The initial part of the policy states that it is defining a term; therefore, it should be moved to the Acronyms and Terms section of the TPM. There is one correction that should be made and that is the changing of the word blunder to oversight. Blunder was felt to not accurately convey what could have been either an active or passive action by the controller. Oversight is a more comprehensive term. The first bullet would then read “to recognize the oversight”:

IFATCA TPM (2019), SEP 7.5 – Controller Intervention Buffer

The Controller Intervention Buffer be defined as:

The time required for the Air Traffic Controller to intervene ensuring that a collision would be averted in the event that a separation standard being applied breaks down. This will include an allowance:

  • to recognize the ‘blunder ’ oversight;
  • to formulate a solution;
  • to convey instructions to the pilot;
  • for the pilot to react and cause the aircraft to achieve the required change of trajectory.


2.5.2. The remainder of the policy remains strong and valid. If conditions or functionality of equipment were to change, ATCOs would need to be made aware of the new situation.

2.6. SEP 7.6 – Interception of Civil Aircraft.

2.6.1. The original paper proposing this Policy was created in 2006; in 2018 there was a change placed in PANS ATM which encompasses the current goals of the Policy. The Policy recommends additional separation in interceptor operations; the PANS ATM allows for the additional separation in exceptional circumstances which interceptor operations would fall under: Larger separations than the specified minima should be applied whenever exceptional circumstances such as unlawful interference or navigational difficulties call for extra precautions. This should be done with due regard to all relevant factors so as to avoid impeding the flow of air traffic by the application of excessive separations.

Note.— Unlawful interference with an aircraft constitutes a case of exceptional circumstances which might require the application of separations larger than the specified minima, between the aircraft being subjected to unlawful interference and other aircraft.

PANS ATM 16th Edition Change 8

The Policy is proposed for deletion since it is now covered within PANS ATM:

IFATCA TPM (2019), SEP 7.6 – Interception of Civil Aircraft

It is recommended to take additional separation, above that required by standard separation, when separating from an interceptor or intercepted aircraft.


2.7. SEP 7.7 – Definitions: Spacing, Separation & Segregation.

2.7.1. In its current condition the policy provides definitions, which are not currently featured in the Acronyms and Terms section of the TPM; however, it does not prescribe any change or goals. It is proposed that these definitions are included in the Acronyms and Terms portion of the TPM to keep their value. Once this move is complete there will be no need to maintain this text as policy and it is therefore proposed for deletion:

IFATCA TPM (2019), SEP 7.7 – Definitions: Spacing, Separation & Segregation

Separation be defined as:

The action within defined airspace of keeping aircraft at such displacements from defined hazards that the risk of collision is limited to an acceptable safe level.

Spacing is defined as:

The application of a displacement equal to or greater than a specific separation minimum between an aircraft and a hazard.

Segregation is defined as:

The application of procedures and design with the purpose of setting apart an exclusive subset of users of the ATM system, based on a defined operational characteristic.



2.8. SEP 7.8 – Visual Separation on Approach.

2.8.1. This policy proposes the amendment of the definition. The Acronyms and Terms section of the TPM reads: “ATSA-VSA – Enhanced traffic situational awareness during visual separation”. Therefore, it is suggested that the policy is deleted since its goals have been accomplished:

IFATCA TPM (2019), SEP 7.8 – Visual Separation on Approach

The description for ATSA-VSA, “Enhanced Visual Separation on Approach”, shall be changed to: “Enhanced traffic situational awareness during visual separation”.



3.1. The Separation portion of the TPM featured some policies that needed updated or removal for a spectrum of reasons. In some cases, the goals have been accomplished and in others the needs or functionality has changed. With continued review the TPM can be kept in an up to date and even easier to use state.


4.1. It is recommended that the abovementioned sections of the Technical and Professional Manual (TPM) be amended accordingly, as described in Section 2 of this working paper.


ICAO. (2014). Implementation of Strategic Lateral Offset Procedures. Montréal, Canada: ICAO.

ICAO. (2016). Procedures for Air Navigation Services – Air Traffic Management (PANS-ATM, Doc 4444) 16th  Ed. Montréal, Canada: ICAO.

ICAO. (2018). Rules of the Air, Annex 2 to the Convention on International Civil Aviation. Montréal, Canada: ICAO.

IFATCA. (2019). IFATCA Technical and Professional Manual (TPM). 2019 Ed. Montréal, Canada: International Federation of Air Traffic Controllers’ Associations.


Last Update: July 26, 2022  

July 20, 2022   243   Jean-Francois Lepage    2022    

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