Automatic Dependent Surveillance – Broadcast

Currently, there are no exemptions for the carriage of ADS-B version 2 equipment in place. SPI-IR mandated airframes shall be compliant by June 7th, 2020.

SDM survey in 2018 found that due to operational and procurement challenges some airlines will ultimately fail to meet the compliance date. Therefore, SDM believes that some very limited discretion should be shown to airlines demonstrating a clear and robust indication of procurement and ADS-B implementation.

EC requested EASA to provide a duly justified revision of the exemptions section of SPI IR. The final decision, embedded in the revision of SPI IR, is expected for publication Q4 2019.

Air Navigation Service Providers reported that there are implementations of ADS-B sensors ongoing to complement redundant surveillance layers, and some limited operational use is already occurring. A high airborne equipage rate will be needed to allow for an ADS-B driven progressive rationalization of the highly redundant Secondary Surveillance Radar network in the European continental airspace.

A number of large European ANSPs announced major surveillance infrastructure renewal programs commencing 2020, which will present an opportunity to progress with ADS-B deployment.

ADS-B Version 2 provides the performance required to safely provide ATC service in the dense and complex European continental airspace.

Version 2 ADS-B conveys improved data accuracy, latency and integrity, borne among others from the requirement to directly wire the Global Navigation Sensor System to the ADS-B Transponder unit.

The two mandates are very similar, however there are a few differences. One difference relates to that the US mandate has additional requirements on the Position data quality as well as operational requirements linked to the position source used, where some are subject to a temporary exemption until 31 December 2024.

Refer to the FAA website for the detailed exemption policy

A well rounded description of the FAA mandate is available here.

At system component level it is expected to happen in an increasing measure; this decision is for each ANSP to make, taking into account the specifics of own operational environment. As a technology, in continental Europe ADS-B is expected to complement, rather than replace, the independent cooperative layer, consisting of Mode S and multilateration systems and to a diminishing part, the legacy Mode A/C radars. The respective EUROCAE Standard for this application is the ED-161 and the deployment is already in progress in Europe.

Work is ongoing in further standardization of integrating ADS-B with independent cooperative sensors.

Based on the surveys, SDM anticipates the mandated fleet to reach the vicinity of 75% in mid-2020, 93% in 2023 and approach 100% in 2025; within a margin that is yet to be determined by future provisions, including the accommodation of a relatively small number of aircraft planned for phase-out before 2025, as well as by the stakeholders’ commitment to implementation. Learning from the experience with the implementation of the US mandate and from recent work carried out by SDM, the two most effective components in promoting compliance are timely clarity on anticipated regulatory action and continued support of the stakeholders in the form of frequent provision of up-to-date information to increase awareness as well as technical and operational coordination. Assuming both are put into effect in Europe, SDM believes that such percentages are reachable objectives.

As to what concerns General Aviation and other types of operations which reside outside of the scope of SPI IR, this domain is currently under the responsibility of EASA; queries and concerns regarding these types of operations should be addressed directly to EASA.

Yes; the mandated ADS-B Version 2 eliminates a large proportion of known causes of abnormal behavior observed in the previous versions. As usual, it will the responsibility of each individual ANSP to independently verify ADS-B performance before committing to a provision of ADS-B enabled ATC service.

Space-based ADS-B is a relatively recent technology which utilizes a network of communication satellites placed in the Low Earth orbit (LEO) to provide ADS-B coverage “from above”. The LEO constellation listens to ADS-B messages broadcast from aircraft and forwards them to subscribers using a low latency link.

The performance of the space-based ADS-B surveillance is sufficient to allow a drastic reduction in ICAO Doc 4444 PANS ATM longitudinal and lateral separation minima for aircraft equipped with ADS-B Out, which is currently on consultation in ICAO. To apply these new separation standards, a number of prescribed conditions must be met, including RNP and RCP. The new standards reduce the applicable minima to 19 NM / 17 NM longitudinal and can be further reduced to 15/14 NM in specific traffic conditions. NAV CANADA and NATS are currently in the process of applying these new separation standards in the NAT Region, with other ICAO NAT ANSPs expected to follow suit.

Space-based ADS-B will also enable continental coverage and ANSPs will be able to procure this as a surveillance service.

Aireon consortium (aireon.com) is the world’s first provider of this service and was recently awarded the Air Navigation Service Provider certificate by EASA. Aireon utilizes the Iridium NEXT network of 66 LEO satellites providing global coverage.