Appendix 1

• Regulation (EU) 2023/1771 found in: ATM/ANS Provision of Services (2017/373) (Mar 2025)

Appendix 1 Regulation (EU) 2023/1771 Identification of individual aircraft using the downlinked aircraft identification feature as required by point ATS.OR.446(b) The downlinked aircraft identification feature shall be used as follows to establish individual aircraft identification: (a) The air traffic services provider shall declare to the Network Manager the airspace volumes where individual aircraft identification is established using the downlinked aircraft identification feature. (b) The conspicuity SSR code A1000 shall be assigned to aircraft where individual aircraft identification is established by using the downlinked aircraft identification feature. (c) Except when one of the conditions set out in point (d) apply, the conspicuity SSR code A1000 shall be assigned to departing aircraft or to aircraft for which, in accordance with point (g), a code change is required, where the following conditions apply: (1) the downlinked aircraft identification matches the corresponding entry in the flight plan for that aircraft; (2) the Network Manager has communicated that the particular aircraft is eligible for the assignment of the conspicuity SSR code A1000. (d) The conspicuity SSR code A1000 shall not be assigned to aircraft referred to in point (c) if any of the following conditions apply: (1) contingency measures that require the assignment of discrete SSR codes to aircraft have been put in place by an air navigation service provider that experiences unplanned ground surveillance sensor outages; (2) exceptional military contingency measures require air navigation service providers to assign discrete SSR codes to aircraft; (3) an aircraft which is eligible for the assignment of the conspicuity SSR code A1000 established in accordance with point (c) exits or is otherwise diverted outside the airspace volume referred to in point (a). (e) Aircraft that are not assigned the conspicuity SSR code A1000 established in accordance with point (c) shall be assigned an SSR code that complies with a code allocation list agreed by the Member States and coordinated with third countries. (f) When an SSR code has been assigned to an aircraft, a check shall be made at the earliest opportunity to confirm that the SSR code set by the pilot is identical to that assigned to the flight. (g) SSR codes assigned to aircraft being transferred from air traffic services providers in neighbouring States shall be automatically checked to see whether the assignments can be retained in compliance with a code allocation list agreed by the Member States and coordinated with third countries. (h) Formal arrangements with the following minimum content shall be established with neighbouring air navigation service providers that establish individual aircraft identification by using discrete SSR codes: (1) an obligation on the neighbouring air navigation service providers to transfer aircraft with verified discrete SSR codes assigned in compliance with a code allocation list agreed by the Member States and coordinated with third countries; (2) an obligation to notify accepting units about any observed irregularity in the operation of airborne constituents of surveillance systems; (i) air traffic services providers shall ensure that the assignment of discrete SSR codes in compliance with a code allocation list agreed by the Member States and coordinated with third countries to establish individual aircraft identification complies with the following: (1) the SSR codes are automatically assigned to aircraft in compliance with a code allocation list agreed by the Member States and coordinated with third countries; (2) the SSR codes assigned to aircraft being transferred from air navigation service providers in neighbouring States are checked to see whether the assignments can be retained in compliance with a code allocation list agreed by the Member States and coordinated with third countries; (3) the SSR codes are classified into different categories to allow for differentiated code assignment; (4) the SSR codes from the different categories referred to in point (3) are assigned according to the directions of flights; (5) multiple simultaneous assignments of the same SSR code are made to flights that operate in code conflict- free directions; (6) the controllers are automatically informed when SSR code assignments are unintentionally duplicated.