2026 ASEE Annual Conference & Exposition

This study presents a model-based integration of Functional Hazard Assessment (FHA) to enhance the safety and reliability of the Bombardier DHC-8 Q400, with a focus on its landing gear systems. Widely recognized for its role in regional aviation, the DHC-8 Q400 has experienced recurring challenges in hydraulic and gear components. This research addresses these challenges by combining FHA with Model-Based Systems Engineering (MBSE) methodologies, enabling early identification of hazards and critical failure modes such as hydraulic leakage, uncommanded braking, and mechanical linkage malfunctions.

Using tools such as SysML and MagicDraw within the MBSE framework, the study develops detailed system models to explore functional interdependencies and failure propagation paths. Through the integration of Failure Modes and Effects Analysis (FMEA), Risk Priority Numbers (RPNs), and subsystem reliability metrics such as Mean Time Between Failures (MTBF) and Mean Time To Repair (MTTR), the methodology enables quantifiable safety evaluation and mitigation strategy validation. The process supports Preliminary System Safety Assessments (PSSA) and aligns with ARP4754A and ARP4761 safety guidelines.

This work demonstrates how MBSE-driven FHA supports traceability, repeatability, and rigor in early-stage system safety analysis. The proposed methodology offers a scalable approach for integrating safety into the system architecture of modern and legacy aircraft, enhancing both operational resilience and certification readiness.