A controls and avionics concept defining sensing, computation, and actuation used to guide, navigate, and control vehicles in air or space. It governs data acquisition, estimation, control logic, and fault handling needed to meet stability and mission objectives. It does not provide safe control without validated software, robust redundancy, and appropriate integrity monitoring. It materially affects safety and mission success by determining guidance accuracy, stability margins, and automation performance. The concept is generally stable, though architectures and computational methods evolve over time.

Principle

Use scenario-based, mission-representative tests that exercise nominal and off-nominal behaviors, include sensor degradations and GNSS outages where relevant, and link each scenario to acceptance criteria and required instrumentation.

Demonstration

Illustrative scenario: simulate GNSS denial during final approach, verify that the navigation filter transitions to inertial/vision aiding, guidance commands maintain required glidepath within specified lateral/vertical errors, and record time-to-recover and residual position uncertainty; run in SIL, HIL and flight replay with injected noise and time-synced ground truth.

Misapplication

Limiting testing to component bench tests (e.g., inertial sensor characterization) without integrated GNC scenarios, resulting in failures only apparent during combined-system operation.

Consequence

A robust test plan validates algorithm robustness, identifies sensor fusion failure cases, supports certification evidence and informs operational limitations and operator procedures.

Reversal

An operational validation or mission rehearsal that focuses on procedures and crew training rather than instrumented measurement of algorithmic performance against quantified criteria.

Boundary

Focuses on guidance and navigation performance and interactions with sensors and higher-level mission logic; excludes primary flight control law unit tests, though it must coordinate with control-law verification where guidance commands interface with controllers.

Semantic Tension

Tension exists between pure algorithm validation (bench/SIL focus) and full-system mission testing (flight trials); the plan must balance coverage, cost and acceptable residual uncertainty in each fidelity tier.

Synthesis

A scenario-driven, fidelity-layered test plan that validates guidance and navigation algorithms and sensor fusion across nominal and degraded conditions, producing measurable evidence for operational readiness while capturing known uncertainties for mitigation.