Development of Policy on Formation Flights Within Controlled Airspace

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Development of Policy on Formation Flights Within Controlled Airspace

30TH ANNUAL CONFERENCE, Port of Spain, Trinidad & Tobago, 22-26 April 1991

WP No. 91

Development of Policy on Formation Flights Within Controlled Airspace


This item was placed on the SC1 work programme when it became known that ICAO was investigating the subject. During initial work on this matter it was noted that from references in ICAO documentation was not clear whether, or not, formation flights within controlled airspace were permitted. This anomaly was recognised by ICAO and the intention was reported to issue amendments to ICAO documents to cover this and other aspects.

It was expected that the proposed amendments would be issued during 1990. At the Acapulco Conference MA’s were asked to provide comments and information on this subject to SC 1, within four weeks of the end of Conference, in order that an input could be formulated. The proposed amendment to ICAO documents was issued on 17th August 1990. The intent of this paper is to notify conference of the input sent to ICAO and to discuss aspects of the subject, drawn from information supplied by MA’s.

The proposed amendment to ICAO documentation will be discussed by the Air Navigation Commission in March 1990 and should be applicable in 1993. The item was discussed within SC 1 and the input from MA’s was considered, in order to assist the Executive Vice President Technical in formulating an IFATCA input to the ICAO proposed amendment. This input was sent to ICAO on the 3rd. February 1991. The proposed amendment introduces the ‘standard formation’ to be operated within set dimensions and is treated as a single aircraft in respect to navigation and position reporting. It has been notified by several MA’s that a standard formation is already in use in their States.

The IFATCA input notes the assumption that standard separation should be applied between standard formations and other aircraft, or other formations. Concern has been expressed that additional separation will be required and it is noted that some States provide additional radar separation when handling formation flights. It would also be possible for vertical separation to be significantly reduced, taking into account the dimensions of a standard formation and the permitted deviation from assigned level by formation leaders and other aircraft being separated from the formation ( this is reduced still further in the case of the separation of two standard formations) . ICAO has noted the implication of the reduction of separation above FL290 in this case.

IFATCA has proposed that the word ‘element’ should be changed to read ‘aircraft’. An element of a formation could be interpreted as more than one aircraft, which could further extend the size of a formation beyond the standard dimensions. This is also the view of IFALPA.

Concern has been expressed, in the IFATCA input, over communication procedures in the event of the break-up of a formation within controlled airspace. In this case each aircraft from the formation would require a separate clearance. If any aircraft did not have the capability to communicate with ATC then it is assumed that normal radio failure procedures would apply.

In the IFATCA input it is noted that the proposed amendment is entitled, ’provisions relating to formation flights by civil aircraft in controlled airspace’. The text of the amendment itself does not particularly mention civil flights, therefore will equally apply to military flights. However, it should be noted that military flights, including formation flights, can be exempted from certain air traffic procedures as stated in PANS-RAC, Part II , Page 2-4, Para. 6.1. notification of this non- compliance need only be given whenever practicable.

Formation flights need special handling, therefore, it is important that the controller is aware whenever a flight is a formation flight. Large aircraft causing extensive wake turbulence require special handling and this is indicated to the controller by the use of the suffix’ heavy’, on initial contact with an ATC frequency. It would ensure that the controller is reminded of the special handling requirements of formation flights if the word ‘formation’ were used in the callsign, at least once on first contact.

To Conclude

The proposed amendment, subject to the changes proposed in the IFATCA input, will improve the situation in respect to the handling of formation flights, particularly in the introduction of a standard formation.

The concern over the additional separation required for formation flights applies equally to procedural separation. Particularly in the case of geographical separation, if the flight contains more than one aircraft it is not clear when the formation can be considered to have passed over the reporting point.

The discussion on the use of the word ‘formation’, although accepted by SC 1 on a majority vote, did not have the full support of the Committee. The opposing view was that there is no need for additional phraseology, in already busy situations, when the presence of a formation flight should be clearly shown by flight data, or on the radar display label. The experience of other members was that flight data is not always available, or accurate, and an additional reminder of a formation flight would be welcomed. Conference is invited to use its wider breadth of experience to decide if Recommendation 4.3 is of significant benefit to warrant the additional phraseology.

It is a principle accepted by conference, during the Technical Policy review presented at Frankfurt, that Technical Policy Statements are only required in those cases when IFATCA holds a position which is different from that of ICAO documents.

The ICAO proposed amendment to Annex 2 (Ref. AN 90/63), concerning the provisions relating to formation flights by civil aircraft in controlled airspace, as amended by the IFATCA input should be accepted.

It is recommended that:

Additional separation, above that provided by standard separation, may be required in some cases, between formation flights and other aircraft, or other formation flights.

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

Last Update: September 20, 2020  

December 4, 2019   326   Jean-Francois Lepage    1991    

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