Ensuring safety in rapidly evolving and increasingly complex aerospace systems requires engineers to account for a myriad of interdependent components. QTSI partners with OEMs, new ventures, and Tier 1 and Tier 2 suppliers to ensure safety is not an afterthought, but an integral part of the design and manufacturing process.
For that, we apply ARP4761(A) In conjunction with its companion standard ARP4754(B), it provides a comprehensive framework for achieving an acceptable level of risk.
QTSI is conversant with working in a regulatory environment governed by certification agencies including the FAA, EASA, and Transport Canada.
Guided by Tailored Application of
What we offer?
Tailored Use of Standards
ARP 4761
ARP 4754
DO-178, DO-254,
DO-326 and DO-356
Compliance with: 25.1309 & 23.2510
Safety Assessment
Tools
Conventional Tools such as: FTAs, DD, MA, and FMEAs
State-of-the-art tools such as: MBSA, CEA, COFFE, etc.
Safety Assessment Softwares: Windchill (WQS), Isograph, and Polarion
System
Expertise
Conventional Aircraft Systems, Advanced Air Mobility (AAM) Rotorcraft, RPAS
S1000D modules
such as: Mechanical, Propulsion, Avionics and Flight Controls
What We Deliver
Full-lifecycle aerospace safety engineering at any stage of your program
Safety Program Plan
Develop the safety plan, define responsibilities, scope, standards, and schedule. The first mandatory deliverable on every aircraft and system program per ARP4761A. One of the first deliverables the certification authorities demand.
Functional Hazard Assessment
AFHA (aircraft level) and SFHA (system level) — failure condition identification, severity classification, and establishment of preliminary safety objectives.
Preliminary & System Safety Assessment
PSSA and SSA — architecture analysis, FTA, FMEA, failure rate quantification, and final compliance matrix demonstrating safety objective achievement.
Common Cause Analysis
ZSA, CMA, and PRA — independence verification for DAL A and DAL B systems. Ensures no single failure or common cause condition can violate a safety objective.
Certification Support
DO-178C (software) and DO-254 (hardware) design assurance. DO-326A/DO-356A aviation cybersecurity. DER/DAE liaison and compliance package preparation for FAA, EASA, and Transport Canada.
Independent Assessment
Third-party safety assessment for TC and STC programs requiring regulatory independence.
Reliability Analysis
Support Reliability Budgeting and prediction/calculation of MTBF based on various available methods, including MIL-HDBK-217F and NPRD.
Continuous Airworthiness
Modification impact analysis for STCs and major changes. Obsolescence assessments. In-service failure analysis. MSG-3 support. Ensuring ongoing compliance with Type Certificate basis.
2
New Aircraft program (part 25)
Full lifecycle SPP through SSA, FAA and TCCA accepted
AAM
eVTOL & STOL Collaboration (Part 23 & 35)
Safety analysis support for top AAM vehicle developer
RPAS
Risk Assessment
Safety of flight assessment for Transport Canada
Rotorcraft
Design Upgrades
(part 27 & 29)
Supplemental type certification support
Programs We've Supported
Case Study: RPAS Certification Support
Challenge: A Canadian RPAS manufacturer developing a complex rotary-wing drone required a full safety program to support their Transport Canada type certificate application. The program involved novel propulsion architecture with no historical failure rate data.
What QTSI delivered: Safety Program Plan, AFHA and SFHA, PSSA and SSA for the flight control and propulsion systems. FTA and FMEA for all DAL A and B functions. Failure rate substantiation using FMEDA methodology. Liaison support with Transport Canada reviewers throughout the process.
Outcome: Certification package accepted by Transport Canada. Safety assessment delivered within program schedule. Client team upskilled on ARP4761A methods during the engagement.
The Standards We Work In
Deep technical expertise in every standard relevant to your aerospace program
ARP4761A - Guidelines for Conducting the Safety Assessment Process
What it is: ARP4761A defines the safety assessment process for civil aircraft and systems — from Safety Program Plan through final SSA. The 2023 revision introduced Model-Based Safety Assessment (MBSA), Cascading Effects Analysis (CEA). It mandates FHA, PSSA, SSA, and CCA at both aircraft and system levels.
What QTSI delivers: QTSI delivers the full ARP4761A process: Safety Program Plans, AFHA, SFHA, PASA, PSSA, SSA, and all Common Cause Analysis types (ZSA, CMA, PRA) including DAL assignments and deriving safety requirements. We work in both traditional tools such as FMEA, FTA and the new MBSA methods.
ARP4754B - Guidelines for Development of Civil Aircraft and Systems
What it is: ARP4754B establishes the development assurance process for civil aircraft — requirements capture, validation, verification, configuration management.
What QTSI delivers: QTSI supports safety requirement management as per ARP4754B, development planning, requirements validation and verification, and integration with safety assessment outputs. We ensure your ARP4754B process correctly interfaces with your ARP4761A safety assessments.
DO-178C - Software Considerations in Airborne Systems
What it is: DO-178C (RTCA) / ED-12C (EUROCAE) defines the process for assuring that airborne software is safe. It establishes Software Levels (DAL A–E) and the planning, development, verification, configuration management, and quality assurance activities required at each level. DAL A software has the most rigorous requirements.
What QTSI delivers: QTSI provides DO-178C compliance support — software planning documentation, requirements management in DOORS or Polarion, software verification support, and liaison with DERs and DAEs for FAA and EASA acceptance.
DO-254 - Design Assurance Guidance for Airborne Electronic Hardware
What it is: DO-254 applies to complex electronic hardware — FPGAs, ASICs, and similar components — used in airborne systems. Like DO-178C for software, it defines Design Assurance Levels and the planning, design, validation, and verification activities required at each level.
What QTSI delivers: QTSI provides DO-254 compliance support for avionics hardware teams — hardware design assurance planning, requirements capture, hardware verification support, and tool qualification for the design flow.
DO-326A / DO-356A - Aviation Cybersecurity
What it is: DO-326A defines the airworthiness security process for aircraft and systems, addressing Intentional Unauthorized Electronic Interaction (IUEI). DO-356A provides security methods and considerations. Together they create the aviation cybersecurity certification framework that FAA and EASA now require for all new and modified products.
What QTSI delivers: QTSI provides aviation cybersecurity compliance support — Security Risk Assessment processes, interface between security assessments and ARP4761A safety assessments, and compliance package preparation.
Tools & Platforms
We deliver in the same toolchains your team already uses — no re-training required.
Ansys Medini Analyze
FMEA, FTA, DFMEA, FHA — integrated model-based safety analysis
IBM DOORS
Requirements management and safety traceability across the V-model
Siemens Polarion
Full lifecycle management, requirements, and V&V traceability
Isograph
FTA, RBD, and reliability analysis for quantitative safety assessment
CAFTA
Failure Tree Analysis (FTA) tool.
Jama
Requirements management and safety traceability across the V-model
What sets us apart?
We are your strategic partner in achieving aerospace system safety with tailored use of safety standards and diverse cutting-edge aerospace technology. Some key contributions include:
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Design and Certification of 2 new civilian aircraft development projects from concept to successful certification phase
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Collaboration with one of the top industry leader in e-VTOL, Advanced Air Mobility (AAM) Vehicles
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Supporting certification and testing of Remotely Piloted Aircraft System (RPAS)
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Supporting safety assessment aircraft specialized in Short Take Off and Landing (STOL)
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Executing system safety assessments for rotorcraft flight controls and avionics
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Certification and Development of multiple systems of different ATA designations
Working on an aerospace certification program?
Whether you're at SPP stage or preparing your final SSA, QTSI can step in at any point in the V-model. Conventional aircraft, eVTOL/AAM, or RPAS — we've done it.
From the Safety Gazette
Practical insights on aerospace safety engineering written by our engineers.
