SCOPE OF THE DOCUMENT

This document includes the definition of the services and the Environmental Conditions relevant to the implementation of the ASPA-FIM System and the operational, safety, performance and interoperability requirements for IM Applications.

NOTE: Requirements that provide protection against intentional behavior causing harm or sabotage are beyond the scope of this document.

NOTE: Requirements related to the recording of ADS-B data for accident or incident investigation purposes are beyond the scope of this document.

ASPA-FIM CONTEXT

The IM System, employing ASPA-FIM with supporting ground capabilities, is the basis of a range of envisioned IM Applications based on an ADS-B “In” function that relies on airborne surveillance information (e.g., ADS-B “Out”) being available for the Target Aircraft. ADS-B Out is scheduled to be implemented throughout the United States (U.S.) National Airspace and Europe by similar rulemaking processes. To support IM Operations, this document places requirements on the quality of surveillance information, which has been developed to be consistent with the ADS-B Out rules wherever possible. While defined and assessed as a self-contained system, it is envisioned that ASPA-FIM will be implemented as part of a larger Aircraft Surveillance Application (ASA) System in which it is integrated with other ADS-B In capabilities. This standard, however, does not consider the interaction, interoperability and transition between ASPA-FIM and other ADS-B In applications and systems.

IM is closely related to the Sequencing and Merging airborne spacing application originally defined in the first package of Ground and Airborne Surveillance Applications enabled by ADS-B and collectively called “Package 1” [5]. IM, with an enabling ASPA-FIM installation, is a superset of Operational Applications, under which Sequencing and Merging resides.

Package 1 is enabled by ADS-B given a sufficient level of equipage of aircraft broadcasting ADS-B information, ground stations, and other aircraft receiving and processing that same data.

Package 1 applications require harmonization of minimum system requirements to facilitate interoperability among applications. This has been accomplished through ED-194B/DO-317B [22], DO-282B [28] and ED-102A/DO-260B [31]. The envisioned applications in Package 1 fall into two categories: ADS-B Package 1 Ground Surveillance Applications (GSA):

• ADS-B-NRA Enhanced ATS in non-radar areas using ADS-B surveillance

• ADS-B-RAD Enhanced ATS in radar areas using ADS-B surveillance

• ADS-B-APT Airport surface surveillance

• ADS-B-ADD Aircraft derived data for Air Traffic Control tools ADS-B Package 1 Airborne Surveillance Applications (ASA):

• ATSA-VSA Enhanced visual separation on approach

• ATSA-ITP In-trail procedure in procedural airspace

• ATSA-AIRB Enhanced traffic situational awareness during flight operations

• ATSA-SURF Enhanced traffic situational awareness on the airport surface

• ASPA-FIM Flight Deck Interval Management

NOTE: ADS-B-RAD is a combination of the former ADS-B-ACC (Area Control Centre) and ADS-B-TMA (Terminal Control Area) which defined ATC services based on ADS-B in en-route and terminal areas, respectively in Package 1.

NOTE: ATSA-AIRB has been combined with the Package 1 definition of ATSA-S&A (“Enhanced Visual Acquisition for See-and-Avoid”).

NOTE: IM, with an enabling ASPA-FIM installation, is a set of functions and procedures defined to support a variety of airborne spacing operations, including the former ASPA-S&M (Sequencing and Merging) application.

Separate publication of the SPR/INTEROP documents for each application will allow States, ANSPs and airspace users to select those applications that are best suited to their operations and needs. However, to ensure seamless growth and global interoperability, any new installation of ADS-B should meet the full minimum requirements for the given data link as specified in the published ADS-B link MOPS.

Since ADS-B Package 1, the SPR process has been applied to expand the capabilities of ASPA-FIM and the considerations in this document. Originally developed as “Advanced Interval Management” or “A-IM,” the envisioned IM Applications include the following:

• Dependent Parallel Runway Operations

• Dependent Crossing or Converging Runway Operations

• Paired Approach – a specific, closely-spaced dependent parallel runway operation

• Generalized IM Operations on Non-Coincident Routes

• Operations enabled by data communications – specifically CPDLC and ATS Winds.

• Sequential IM Operations These applications, and the analysis to support them, are described throughout the document. Scenarios illustrating specific IM Operations within the context of these applications are included in Section A.4. This list is not intended to be exhaustive, however, and additional IM Applications may be identified at a later time. Any additional IM Application must meet minimum equipment performance and safety requirements before resulting IM Operations can be conducted.

ASSUMED AIRBORNE AND GROUND GENERIC SURVEILLANCE FUNCTIONAL ARCHITECTURE

Figure 1.1 presents the generic surveillance functional architecture to support all Package 1 applications. The figure identifies the airborne domains and the ground domain associated with Ground and Airborne Surveillance Applications enabled by ADS-B. The airborne domain consists of the Transmit Aircraft Domain and the Receive Aircraft Domain. The Transmit Aircraft Domain represents the functions associated with providing the ADS-B Out capability needed to support ground-based or aircraft-based surveillance applications. The Receive Aircraft Domain provides the ADS-B In capability to host Airborne Surveillance Applications. The Ground Domain represents the capability to host ground-based surveillance applications in support of Air Traffic Services.

Figure 1.1 also identifies the system functions and functional interfaces (small lines with associated letters and numbers, e.g., B1) associated with the aircraft domains and the ground domain. The figure identifies the functional interfaces (e.g., D, G1) to which the Safety and Performance Requirements are allocated. These interfaces are referenced throughout the document where requirements are provided.

General functional capabilities and key aspects of the architecture are specified below.

For the Receive Aircraft Domain:

• The minimum surveillance functional architecture includes:

− reception of ADS-B messages (represented by the ADS-B Receive Function);

− ownship sensor data processing;

− surveillance data processing, and applications-specific processing (represented by the Airborne Surveillance and Separation Assurance Processing Function [ASSAP]); and

− the provision of necessary information to the flight crew by the Traffic Display Function and its associated control interface.

• Requirements allocated to the Receive Aircraft Domain are measured from the point of reception (interface D) for ADS-B information, the output of the aircraft sensors and systems (interface B2) for ownship information, or the reception/conveyance (interface H) of data communication, through the conveyance of needed information to the flight crew (interface G1).

NOTE: ADS-R (Automatic Dependent Surveillance – Rebroadcast) data is shown in Figure 1.1 as a potential other source of surveillance data. In addition to ADS-B, this source may be employed for some of the Package 1 applications. While some assumptions made in the Operational Performance Assessment (OPA) take into account known performances of ADS-R (e.g., latency), this document makes no specific conclusions as to their suitability to support ASPA-FIM.

For the Transmit Aircraft Domain:

• The minimum surveillance functional architecture includes onboard aircraft sensors and associated processing (represented by the Surveillance Transmit Processing Function [STP]) and the subsequent formulation of ADS-B messages to be transmitted (represented by the ADS-B Transmit Function).

• Assumptions placed on the Transmit Aircraft Domain are measured from:

− the time of measurement of sensor data (interface A1 for positioning data);

− sensor outputs and flight crew control panel inputs, e.g., Aircraft Identification (interface B1); and

− at the poin t of transmission of ADS-B Out (interface D).

For the Ground Domain:

• The functional architecture for the generic ASA/GSA systems includes an ADS-B Receive Function, an Air Traffic Control (ATC) Processing Function and an ATC Surveillance Data Display Function.

For this ASPA-FIM standard, no specific analysis is performed to derive specific ground functionality or performance requirements for the ground component of the larger IM System. Assumptions are used where appropriate on ground capabilities so that analysis can derive what is needed from ASPA-FIM to support the provided IM Clearances from the ground. ANSPs implementing IM will need to perform appropriate assessments to ensure that the ground domain meets these assumptions or appropriate changes are made to the requirements allocated to the Receive Airborne Domain (i.e., IM Aircraft).

The additional Ground Domain and Receive Aircraft Domain capabilities to process, transmit, and receive Data Communications were also analyzed. The resultant minimum requirements will apply to those functional architectures that include Data Communications for IM.