Aircraft Communications Addressing and Reporting System (ACARS)

The Aircraft Communications Addressing and Reporting System (ACARS) is the air-ground data link necessary for global communication of vital information, like AOC and ATC messages for commercial airlines and Global Air Traffic Management (GATM) /Mobility 21 (M21) information for military applications. ACARS messages are exchanged via VHF, HF, or SATCOM links with Data link Service Providers (DSP) operating terrestrial communication networks, which uplink and downlink ACARS messages to and from aircraft and provide routing to and from terrestrial Command and Control (C2) systems.

Honeywell developed Secure ACARS to satisfy the commercial airline industry's need for an ACARS security solution based on recognized industry standards. Secure ACARSleverages ATN Security Services cryptographic framework and Public Key Infrastructure to provide airlines and aircraft owners with a cost-effective migration path to ATN (ICAO ATN SARPs, Edition 3).

With Secure ACARS, commercial airlines and aircraft owners realize significant operational benefits, including: 

Confidence in the Sender - Authentication provides message recipients with      assurance that the message source is as claimed.

Confidence in the Received Data - Message digests offer greater data      integrity than CRCs.

Protected Data - Encryption protects airline proprietary and passenger      sensitive message content from disclosure to unauthorized entities.

Reduced Datalink Costs - Data compression reduces transmitted ACARS      message size by up to 35% in the aggregate.

For military applications, Honeywell expanded the security protocols to satisfy the military operational need for information assurance. Designed as a software-only upgrade for GATM data link avionics, Secure ACARS employs US Government approved cryptographic algorithms to provide the end-to-end authentication, integrity, and confidentiality security services necessary to protect official Sensitive-Unclassified communications between aircrews and Component Force decision makers.

Examples of GATM-specific messages exchanged via the ACARS data link and protected by Secure ACARS include:

En Route Position Reports

Mission Clearances

Air Drop and Air Refueling Reports

Flight Plan Requests and Updates

Flight Plan Diversion

Cargo Reports

Free-text Messages

Both the military and commercial Secure ACARS systems offer the flexibility of user-configurable security policy, and once configured, operation is fully automated and transparent so that there is no impact on pilot/aircrew workload.