Aircraft Information Network System (AINS) and the EFB

The first eleven articles covered the datalink half of the information systems; the other half is the AINS (Aircraft Information Network System) and the crew's daily tool, the EFB (Electronic Flight Bag). The AINS is the aircraft's "Ethernet plus servers", letting the crew compute performance and consult documentation, letting maintenance pull fault data, and linking the aircraft to the airline's ground network.

The focus here is not a menu but two concepts: (1) the AINS splits into an Open World part and an Avionics part, isolated by the SIU security gateway; (2) the EFB is the flight-crew application on the Open World side.

1. What the AINS is — an onboard information network

The AMM defines the AINS and its customers. Per AMM 46-00-00:

The AINS consists of: a server providing a host-platform for maintenance and operations applications; a secured interface to the avionics; a virtual link between the Ethernet Local Area Network (ELAN) of the aircraft and the ground-based information system of the airline. This system acquires, stores, processes and transmits avionics-related data to: the maintenance operator [...]; the flight crew to perform performance calculations, consult documentation, etc.; the airline network via the airport ground-based network.

In one line: the AINS is the aircraft's "server + Ethernet + pipe to the ground", with three customers — maintenance, flight crew, airline.

2. Two parts — Open World versus Avionics

The AINS (part of the FlySmart with Airbus system) splits in two. Per AMM 46-11-00:

The AINS is composed of two sub-systems: the AINS Open World part [and] the AINS Avionics part. The AINS Open World part consists of an integrated avionics file server which provides a host-platform for maintenance and operations applications, and a link between aircraft Ethernet Local Area Network (ELAN) and airline ground-based information system. The AINS Avionics part, which contains the Server Interface Unit (SIU) [...], is a secured interface to the avionics.

3. The SIU security gateway — why isolate

The SIU's core role is a security gateway. Per AMM 46-11-00:

The main services offered by the AINS Avionics part are: to provide a secured gateway function between 'Avionics part' and 'Open World part' through the SIU, so as to provide avionics data from/to applications; to provide secure networks capabilities on-board the aircraft.

[!warning]- Information security: the EFB "open world" must never touch the avionics directly This is a modern-airliner information-security cornerstone. The open world (EFB, airline applications, ground/internet-connectable) is "untrusted"; the avionics (FMS/ADIRS/flight controls/engines) is "safety-critical". The SIU is the firewall/gateway between them: it feeds avionics data to the EFB applications one-way and under control (FMS position, ADIRS data for performance calculation), while filtering and controlling any request from the open world toward the avionics, so open-world software/malware/attack cannot reach the avionics. That is the point of the "open world vs avionics" split — a gateway separating "the thing that goes online" from "the thing that flies the aircraft". The SIU takes ADIRS data from the IR/ADR bus 4 and data from the FMS/DMC/SDAC/FWC, all through its gate.

4. The EFB — performance and documentation

On the open-world side the crew touch the EFB — operations applications hosted on the AINS open-world server, used to:

• compute performance (take-off/landing performance, loading);
• consult documentation (manuals, charts, checklists).

These electronify the paper flight bag. Removing the SIU (AMM §3.C) also loses the MCDU3–CMC link, the CMC–printer link, the FSA menu, and the gatelink/cabin-wireless — so the EFB/AINS is also the path for maintenance data (CMC/printer).

5. Configuration note

[!note]- Configuration: the specific AINS/EFB definition follows the operator Optional-equipment content here follows the general AINS description that applies to all in the maintenance manual. In the main library the detailed AINS description carries configuration splits, so an aircraft's specific AINS/EFB variant description follows the operator's actual EFB configuration and the applicable FCOM/AMM section for that aircraft. This article teaches the applicable-to-all architecture and security concept; the item-by-item detail is for operator confirmation. The cabin/passenger information networks are a cabin layer and are not covered here (article 1 boundary).

Self-test

[!note]- Q1. What is the AINS, and who are its three customers? An onboard server + Ethernet + link to the ground network; customers: maintenance, flight crew, airline.

[!note]- Q2. What are the AINS's two parts, and what is the SIU's role? Open World (EFB host + ground link) and Avionics (SIU). The SIU is the secured gateway between them.

[!note]- Q3. Why isolate the open world from the avionics, and how does the SIU protect the avionics? The open world is untrusted, the avionics safety-critical; the SIU is a firewall — feeding avionics data to the EFB one-way while filtering any open-world request toward the avionics.

[!note]- Q4. What does the crew use the EFB for, and what is lost if the SIU is removed? Performance calculation and documentation. Removing the SIU loses the MCDU3–CMC and CMC–printer links, the FSA menu, and gatelink/cabin-wireless.

Key takeaways

References

• AMM 46-00-00 — AINS definition (server + secured avionics interface + ELAN↔airline link); three customers.
• AMM 46-11-00 — AINS as part of FSA; Open World vs Avionics; SIU security gateway; effects of SIU removal.

Independent study material, not an Airbus publication and not endorsed by the manufacturer. Always defer to the current operator FCOM, FCTM, and QRH for operational use; the specific AINS/EFB configuration follows the operator.