Separation Between Units Without Procedural Agreement

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Separation Between Units Without Procedural Agreement

55TH ANNUAL CONFERENCE, Las Vegas, USA, 14-18 March 2016

WP No. 309

Separation Between Units Without Procedural Agreement

Presented by PLC


In some areas separation between aircraft seems to be achieved merely by those aircraft being under the control of different authorities, with no agreed procedure between the authorities as to who is providing the separation and how. This paper aims to look at this and seek ways of providing and ensuring standard separation.


1.1 This paper was introduced by Israel where problems are experienced with two aerodromes in close proximity on either side of the FIR boundary; Israel and Jordan. Although there is a Letter of Agreement (LoA) between these countries, standard separation is not always provided – e.g. for aircraft on final 03 in Eilat and on final 01 in Aqaba nor for two aircraft over the Gulf of Eilat/Aqaba; nor for aircraft departing in the same direction. Moreover, no coordination between the two ATM units is executed, as traffic in the countries concerned are considered ‘being segregated’.

1.2 IFATCA has no policy regarding this issue. The goal of this paper is to find other ATC Units that encounter similar situations and create IFATCA policy (if required) to offer guidance to these units.


2.1 The air traffic control system around the world is based upon a series of FIRs each controlled by one executive agency with responsibility for the safe separation of aircraft within his area.

2.2 Where two FIRs meet, procedures should be put in place to ensure separation between aircraft under the control of two different controllers.

2.3 This statement holds when the ATC Units are within one FIR, straddle the boundary of two or more FIRs, or meet along an FIR boundary.

2.4 The complexity or simplicity of it is to be determined by the relevant National Security Agencies (NSAs). It could be as simple as ‘all controllers to ensure aircraft remain a minimum of 2.5nm from the FIR boundary’ for example, thus ensuring 5nm separation. Merely having aircraft separated by virtue of being on either side of ‘magic lines’ on maps or radar displays can cause serious safety issues. Without agreed and adhered to procedures, the potential for a breakdown in aircraft separation increases.

2.5 Airspace users expect to be provided with defined separation standards when operating in controlled airspace. Controllers are obliged to meet such standards.

2.6 From the ICAO perspective, when aircraft are unable to remain within the FIR boundary and no agreement is in place, contingency procedures should be used.

2.7 There are areas in the world where disputes on the authority of airspace exist. This can produce problematic issues when it comes to creating, maintaining, and utilising procedures to ensure safe separation of aircraft. These, however, are political issues, a solution for which should be found through political processes.

2.8 Where political will is lacking, ANSPs should be encouraged to put the safety of the traveling public first and come to an agreement on procedures for separation. ICAO and other applicable international bodies should be encouraged to assist and/or mediate in the process when States/ANSPs are unwilling or unable to reach an agreement.

2.9 ICAO has published requirements for separation (PANS-ATM Chapter 5):

“At all times whilst under the control of an ATCO, aircraft must be provided with standard separation.”


2.10 A lack of defined separation is not acceptable; standards should be prescribed and adhered to at all times.


3.1 The IFATCA Manual contains no policy on this issue.

3.2 Having a situation where aircraft are considered to be separated by merely being on one side or the other of a border is not acceptable. Separation standards should be in place and applied.

3.3 States and ANSPs should endeavour to overcome/sidestep political issues in order to ensure that primary objectives (i.e. safe separation of aircraft) are met.


4.1 It is recommended that IFATCA policy is:

MA’s experiencing deficiencies in separation procedures in border areas due to issues between neighbouring States shall call upon the appropriate authorities to enable safe ATS provision in such areas.

And is included in the IFATCA Technical and Professional Manual.

Last Update: October 1, 2020  

December 22, 2019   284   Jean-Francois Lepage    2016    

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