ARP 4761A defines the safety assessment process for civil aircraft and systems — the methods and the analytical flow that demonstrate a design meets its safety objectives. In practice the hard part is not any single analysis; it is keeping the whole chain consistent as the design changes. Safety Lab Aero is built around that chain.
The process, mapped to the tool
- FHA — Aircraft and System Functional Hazard Assessments. Log each failure condition, classify severity, and derive the quantitative probability target and development assurance level from your certification basis.
- PASA / PSSA — preliminary safety assessment. Build fault trees, allocate budgets and DALs top-down, and capture the safety requirements that fall out.
- SSA — system safety assessment. Quantify against the targets with the bottom-up evidence in place and confirm every failure condition is covered.
- Supporting analyses — FMEA for bottom-up evidence and CMA, PRA and ZSA for independence, particular risks and zonal effects.
Traceability is the product
Functions trace to failure conditions; failure conditions to fault trees; trees to FMEA modes, library components and items; analyses to requirements; requirements to verification. Because it is one data model, you can open any failure condition and see its complete end-to-end safety case — and exactly where it is incomplete — rather than reconciling a folder of disconnected spreadsheets and documents.
Certification bases supported
14 CFR Part 25, Part 23 (Classes I–IV), Part 27/29 rotorcraft, Part 33/35 engines and propellers, EASA SC-VTOL (Basic / Enhanced), Part 450 commercial space, Part 107 UAS, and a user-defined custom basis. The basis drives the severity-to-probability targets and the DAL ladder automatically.
Built for the deliverable, not just the analysis
Safety Lab Aero generates the ARP 4761A artifact set (AFHA, PASA, PSSA, SSA, SFHA, ZSA, PRA, CMA) as editable, section-level documents, plus a DO-330 tool-qualification dossier so analyses produced by the tool can claim certification credit.
Frequently asked questions
What is the difference between ARP 4761A and ARP 4754B?
ARP 4761A is the safety assessment process (FHA, PSSA, SSA and the supporting analyses). ARP 4754B is the development-assurance process for the aircraft and its systems, including how DALs are assigned and managed. Safety Lab Aero covers both and keeps them connected.
Does it support Part 23, SC-VTOL and Part 450 as well as Part 25?
Yes. The certification basis is selectable, and it sets the severity-to-probability targets and DAL allocations for that basis automatically, including Part 23 classes, EASA SC-VTOL Basic/Enhanced and Part 450.
See it on your own analysis
Safety Lab Aero keeps functions, hazards, fault trees, FMEA, common-cause, requirements and verification in one connected model — from FHA to a certification-ready evidence package.