From legacy to leading edge: FACE and MOSA transform technology integration in defense avionics

Story

May 07, 2026

Joe Richmond-Knight

SYSGO

As defense programs demand greater agility and cost-effectiveness, the Future Airborne Capability Environment, or FACE, Technical Standard and the modular open systems approach (MOSA) are providing program managers, systems integrators, and avionics architects with the architectural foundation for flexible, risk-reduced technology upgrades in military avionics.

The ongoing evolution of military aviation demands faster technology integration, greater cost control, enhanced security, and long-term adaptability. The Future Airborne Capability Environment, or FACE, Technical Standard and the modular open systems approach (MOSA) are at the heart of this transformation, providing the technical and conceptual foundation for modular, interoperable, and future-proof avionics. The FACE approach and MOSA enable risk-reduced integration, lower life cycle costs, and support secure and agile upgrades.

Investment for long-term advantage

The shift toward modular, open architectures is more than just a technical evolution. It is also a strategic investment with major implications for cost, risk, and operational flexibility for defense programs.

Implementing open standards like FACE and MOSA requires an initial investment in technical and organizational change. However, long-term savings and operational flexibility are substantial.

By decoupling platform architecture from functional logic, system providers can reuse certified modules across multiple projects, reducing vendor-lock-in and minimizing costly reintegration. The FACE Registry, a publicly accessible marketplace for certified software modules, further amplifies these benefits by increasing visibility, accelerating procurement and fostering a competitive environment where both large and small vendors can participate equally.

These advantages extend well beyond the initial development stage. The clear separation of system modules facilitates easy replacement or upgrade of individual components. It enables parallel modernization and targeted integration of new technologies with minimal disruption. This approach streamlines maintenance, addresses hardware obsolescence, and keeps testing efforts and costs predictable. Thus, modernization becomes scalable and auditable, delivering tangible cost savings and operational readiness throughout the system’s life cycle.

Security architecture and multilevel security (MLS): Building trust into the system

As avionics systems become more interconnected and software-defined, security becomes mission-critical. Adopting a FACE approach addresses this challenge with a robust security architecture developed by the Security Subcommittee of the FACE Technical Working Group. The standard enables the integration of components with different security requirements and supports physical and logical separation via partitioning technologies such as ARINC 653.

A key focus is multilevel security (MLS), which allows modules with different classification levels, such as open navigation systems and classified mission algorithms, to coexist securely on shared hardware. The system’s resilience is further strengthened by secure communication interfaces in the transport services segment (TSS) and the ability to define dedicated policies for security-relevant data paths. Domain-specific security mechanisms, including data encryption and access control, can be implemented without compromising interoperability. This architecture, combined with standardized data models, meets stringent military requirements and is equally applicable to both critical infrastructure and civilian aviation.

Data exchange and compatibility: The role of the TSS

One major advantage of the FACE standard is the flexibility of the TSS, which acts as a mediation layer between software components. The TSS can host middleware functionalities that go beyond basic data transport, including versioning, semantic data conversion, validation, and integration of messaging protocols.

This flexibility is particularly valuable for platforms with mixed-generation systems. For example, a modernized targeting system can access data from an older navigation module without requiring direct interface modifications. The middleware then acts as an adaptive layer that supports MOSA’s central objective of enabling technology updates independently of platform structure. This approach preserves architectural integrity and accelerates the pace of modernization.

The FACE Registry: Certification and marketplace

Building upon its role in terms of cost and innovation, the FACE Registry also reduces integration risk and sustains competitiveness through its rigorous certification process.

The FACE Registry is more than just a directory. It serves as a central hub where program managers, system integrators, and developers can discover, compare, and source certified Units of Conformance (UoC) with confidence. Each component listed in the registry undergoes a formal conformance process to ensure interoperability within the FACE architecture. This process provides assurance that only rigorously tested, standard-compliant modules are available for integration. Procurement and integration are streamlined, and trust is built across the defense avionics ecosystem.

The path to FACE conformance involves three stages:

Conformance Test Suite (CTS): Automated testing by the developer
Verification Authority (VA): Independent validation by authorized bodies
Conformance Authority (CA): Final certification and entry into the registry

By leveraging the registry, organizations can reduce integration risk, accelerate modernization, and maintain a competitive edge in a rapidly evolving market.

Common misconceptions about FACE approach

Despite its widespread adoption, there are still several misconceptions about the FACE Technical Standard. One common belief is that all software on a platform must be FACE aligned or certified conformant. In reality, the standard is primarily designed for interchangeable or reusable modules, not for every line of code. Another misconception is that the FACE approach guarantees performance. In fact, the standard defines interfaces to ensure interoperability, but it does not dictate the software’s functionality or speed.

Concerns about intellectual property are also often misplaced. Although the FACE standard promotes open interfaces, developers are not required to relinquish ownership of their proprietary technology. Intellectual property remains firmly with the creator. Additionally, some believe that the FACE standard is only relevant for new systems when, in fact, retrofitting existing platforms is a central goal of the standard. Finally, although initial implementation costs may be higher, the long-term benefits of module reuse and increased competition can result in significant cost savings over a program’s life cycle.

Empowering developers and architects

The successful implementation of the FACE approach and MOSA is supported by a wide range of tools and training resources. The BALSA reference project [The Open Group-supported Basic Avionics Light-weight Source Archetype environment], for example, provides a minimal, functional example environment that demonstrates how to build a simple but complete FACE compliant application. This is complemented by detailed documentation, guidelines for software vendors, integrators, and project managers, as well as regularly updated training programs. These resources are critical for steering projects in the right direction from the start and avoiding costly missteps.

Harmonizing standards for operational capability

Modern defense systems rarely operate in isolation. The continued advancement of open systems approaches requires the integration of various architectural standards into one overarching system. While the FACE approach modularizes and standardizes platform software, other standards like the Sensor Open Systems Architecture, or SOSA, Technical Standard and the Air Force Research Lab’s Weapon Open Systems Architecture, or WOSA, address specific domains such as sensors and weapons.

Successfully integrating the FACE approach, the SOSA Technical Standard, and WOSA requires harmonized data models and interface definitions. For example, integration enables a SOSA compliant infrared (IR) seeker to be leveraged as part of a WOSA missile system; the system then communicates with the mission computer of the carrier aircraft through FACE compliant middleware. Such end-to-end architecture supports modular upgrades, mission-wide interoperability, and multinational deployment scenarios, all of which are key factors for future-proof defense structures.

Going forward

In combination with MOSA, the FACE approach establishes a conceptual and technical basis for a new generation of open, maintainable, cost-effective, and secure avionics systems. These standards enable modularity, interoperability, and streamlined certification, thereby empowering defense programs to transition from legacy architectures to leading-edge capabilities. As the demands on military aviation continue to evolve, the FACE approach and MOSA provide the necessary tools and frameworks to modernize existing platforms, integrate new technologies, and ensure long-term operational readiness.

Joe Richmond-Knight is regional sales manager at SYSGO and supports customers in the adoption of safety- and security-critical software architectures for embedded and avionics systems. With a background in embedded systems, IoT, and complex data acquisition, Joe brings both technical and commercial perspectives to system integration challenges. Joe joined SYSGO in 2022, where he worked as a field application engineer and solutions architect. Before SYSGO, he held engineering leadership roles in PropTech and InsurTech startups. Joe holds a degree in computer systems engineering from the University of Kent and is a member of the Institution of Engineering and Technology (IET).

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