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System Safety & Reliability
Safety Engineering for Trade & Architectural Feasibility Studies

At IDA, safety engineering is applied early in the design process, enabling informed trade studies and architectural feasibility assessments. Our team has extensive experience in avionics, flight controls, electric propulsion, and other complex safety-critical systems, allowing us to anticipate potential hazards while balancing performance, cost, and certification objectives. By embedding safety considerations into architectural decisions, we help our clients avoid late-stage redesigns, de-risk innovative technologies, and accelerate pathways to certification.

Generate Safety Artifacts for A/C, System & Equipment

In alignment with ARP-4761A, we develop and deliver complete sets of safety artifacts across the aircraft, system, and equipment levels. The following artifacts form the basis for certification evidence and operational approval. IDAs structured documentation ensures traceability from high-level safety objectives down to equipment-level analyses, providing regulators and customers with confidence in the completeness and consistency of the safety assessment process.

A/C Functional Hazard Assessment (AFHA)
We perform Functional Hazard Assessment to identify, classify, and assess potential functional failures and their effects on aircraft safety. Our engineers ensure that each function’s failure conditions are clearly linked to system safety objectives and development assurance levels in accordance with ARP-4761A and related EASA guidance.
Preliminary A/C Safety Assessment (PASA) & A/C Safety Assessment (ASA)
We conduct comprehensive (Preliminary) Aircraft Safety Assessments to evaluate system interactions, identify potential failure combinations, and demonstrate compliance with safety objectives. Our approach follows ARP-4754B and ARP-4761A processes, ensuring that all aircraft-level hazards are systematically analyzed, mitigated, and verified through a traceable safety case.
System Functional Hazard Assessment (SFHA)
We carry out System-Level Functional Hazard Assessment to identify and classify potential functional failures within each system and assess their impact on aircraft safety. Our analyses, performed in line with ARP-4761A guidance, ensure that system-level hazards are correctly derived, categorised, and allocated to drive robust safety and development assurance requirements.
Preliminary System Safety Assessment (PSSA) & System Safety Assessment (SSA)
We perform detailed (Preliminary) System Safety Assessments to demonstrate that each system meets its allocated safety requirements and contributes correctly to overall aircraft safety objectives. Using methods defined in ARP-4761A, we develop and analyze FTA, FMEA, and CCA to verify that system architectures and implementations achieve the required integrity and development assurance levels.
Common Cause Analysis (CCA) incl. Zonal Safety Analysis (ZSA), Common Mode Analysis (CMA) & Particular Risk Analysis (PRA)
We perform comprehensive Common Cause Analyses, including Zonal Safety Analysis, Common Mode Analysis, and Particular Risk Analysis, to identify and mitigate dependencies that could compromise system independence. Our systematic approach, consistent with ARP-4761A, ensures that physical, functional, and environmental common causes are thoroughly assessed and controlled to maintain compliance with aircraft safety objectives.
Intrinsic Hazard Analysis (IHA)
We conduct Intrinsic Hazard Analysis to identify and evaluate hazards inherent to a system, subsystem, or component, independent of specific failures or malfunctions. Our analyses ensure that inherent risks — such as those arising from energy sources, materials, or operational characteristics — are understood, mitigated, and properly managed within the overall safety framework.
Failure Modes and Effects (and Criticality) Analysis (FMEA/FMECA)
We perform detailed Failure Modes and Effects Analyses (FMEA) and Failure Modes, Effects, and Criticality Analyses (FMECA) to systematically identify potential component or functional failures and assess their impact on system performance and safety. Our structured approach ensures that failure causes, effects, and criticalities are quantified and that resulting mitigation actions are effectively integrated into the design and verification process in accordance with ARP-4761A and industry best practices.
Safety Requirements Verification & Validation (V&V) Evidence
To guide decision-making, we conduct trade studies that compare architectural alternatives and identify optimal solutions. With extensive experience in analysing electric fault effects in hybrid-electric propulsion systems, we provide insights that strengthen safety, performance, and compliance in next-generation aircraft designs.
Safety Case
We create, document and maintain your safety case and the Safety Assessment Report.
Intrinsic Hazard Analysis

We actively promote the use of Intrinsic Hazard Analysis (IHA) as an early design tool, particularly valuable for novel or emerging technologies such as electric propulsion and distributed systems. Applying IHA at the concept stage helps identify inherent hazards before they become embedded in the architecture, enabling safer designs and reducing costly redesigns later in development. Maria K., one of our safety experts, serves as the co-chair of the EUROCAE Working Group developing the IHA standard, ensuring that IDA remains deeply involved in shaping the future of system safety practices.

Training, Mentoring and Audits
Training and Mentoring
We also provide training and mentoring to engineering teams, helping them understand and apply safety assessment principles effectively within their own development programs. This knowledge transfer ensures that safety thinking becomes an integral part of each engineer’s design mindset.
Audits and Reviews
In addition to analysis and documentation, IDA conducts audits, independent checks, and process compliance reviews to verify conformance with ARP-4761A and related certification standards. These activities ensure that internal and supplier safety processes meet the rigor expected by aviation authorities and prime contractors.
Certification Preparation & Liaison with Authorities

Navigating certification requirements is one of the most critical steps in bringing aerospace products to market. IDA assists clients in preparing for certification by aligning safety and reliability evidence with regulatory expectations. We act as a bridge between engineering teams and authorities, ensuring that safety cases are clearly presented, requirements are traceable, and documentation meets the standards of agencies such as EASA and FAA. This liaison role reduces uncertainty in the approval process, streamlines interactions with regulators, and accelerates time to certification.

Reliability as a Foundation for Safety Verification
Reliability Engineering
Reliability engineering at IDA is applied primarily to support and verify the assumptions made in the System Safety Assessment (SSA). Through MTBF calculations, reliability predictions and optimizations, we provide quantitative evidence that system designs can achieve their required safety objectives. Methods such as Reliability Block Diagrams (RBDs) and Failure Modes, Effects (and Criticality) Analyses [FME(C)As] are used to model system behaviour, quantify failure probabilities, and validate redundancy strategies.
Standards and Guidance
Our reliability analyses follow established aerospace and electronic standards, including:
  • IEC 60812 FMEA, IEC 61078 RBDs, IEC 61709
  • MIL-STD-1629A FMEA, MIL-HDBK-217, MIL-HDBK-338B, MIL-HDBK-217, MIL-HDBK-338B
  • ANSI/VITA 51.1, FIDES, Telcordia SR-332
  • NPRD and EPRD, NSWC Mechanical, and SN 29500
By integrating these standards and datasets into our reliability modelling, we ensure that all quantitative assumptions underlying safety analyses are robust, traceable, and defensible to certification authorities.
Certification Verification Engineer

We can independently check your systems design artifacts and verification evidence as a Certification Verification Engineer (CVE) in your design organisation.

Fault Tree Analysis (FTA) Modelling Expertise
Tool Chain

IDA has extensive experience in developing and maintaining Fault Tree Analysis (FTA) models to support both quantitative and qualitative safety assessments. Our team has worked with a wide range of industry-standard FTA and reliability modelling tools, including:

  • Isograph Reliability Workbench (FaultTree+)
  • ITEM
  • CAFTA
  • Relyence
  • Arbre Analyste

This familiarity allows us to efficiently adapt to our clients preferred toolchains and ensure full compatibility with existing program data and certification deliverables.

Transparency, Traceability, and Verification
Beyond tool proficiency, we emphasize model transparency, traceability, and cross-verification to maintain consistency between FTAs, FMEAs, and Reliability Block Diagrams. Whether building new models from system architecture data or reviewing existing analyses for compliance, IDA ensures that FTA results integrate seamlessly into the overall safety case.
Human Factors in Safety & Reliability
Human Factors Engineering
Human performance is a key consideration within the ARP-4761A safety assessment framework. At IDA, we integrate Human Factors Engineering (HFE) into Functional Hazard Assessments (FHA), System Safety Assessments (SSA), and operational analyses to evaluate how crew actions, workload, and interface design influence system safety. By identifying potential human errors and performance limitations early, we help ensure that mitigations - whether procedural, design-based, or training related are implemented effectively.
Standards and Guidance
Our approach follows ARP-4761A, ARP-4754B, and established regulatory guidance including the FAA Human Factors Design Standard (HFDS), EASA Human Factors CRI, and MIL-STD-1472G, ensuring that safety objectives consider both system reliability and realistic human performance throughout operation and maintenance.