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Short answer: Aviation safety is the discipline of managing the risk of aircraft accidents and incidents. In current regulation it is organised as a safety management system (SMS) with four components: safety policy, safety risk management, safety assurance and safety promotion. ICAO sets the State-level framework in Annex 19, and the FAA applies an operator-level SMS rule in 14 CFR Part 5.
General information for researchers and safety staff. This is not a compliance opinion for any specific operator.
Definition and scope
The regulatory text is more precise than most overviews. 14 CFR 5.3 defines a hazard as “a condition or an object that could foreseeably cause or contribute to an incident or aircraft accident”, and risk as “the composite of predicted severity and likelihood of the potential effect of a hazard.” A hazard is therefore a condition, while risk is a judgement about how severe and how likely its consequence would be. Aviation safety work is the systematic handling of both.
The same section defines the safety management system as “the formal, top-down, organization-wide approach to managing safety risk”. ICAO describes the State Safety Programme (SSP) as the foundation of a proactive safety strategy, implemented alongside service providers’ SMS.
How safety is managed: the four SMS components
Under 14 CFR 5.5 an SMS must contain at least four components, each with its own subpart of Part 5.
- Safety policy (subpart B).
- Safety risk management (subpart C). Defined in 5.3 as a process “composed of describing the system, identifying the hazards,” and “analyzing, assessing, and controlling risk.”
- Safety assurance (subpart D). “Processes within the SMS that function systematically to ensure the performance and effectiveness of safety risk controls.”
- Safety promotion (subpart E). “A combination of training and communication of safety information.”
Section 5.5 also requires that the SMS be “appropriate to the size, scope, and complexity of the person’s organization”.
State level versus operator level
Two layers are often confused. A State manages safety nationally through its SSP, and service providers run an SMS inside their own organisations. The table compares the two instruments as described in the sources below.
| Item | ICAO Annex 19 | FAA 14 CFR Part 5 |
|---|---|---|
| Level | International standards and recommended practices on safety management | US rule requiring an SMS in specified organisations |
| History and structure | 1st edition adopted 25 February 2013, applicable 14 November 2013; it consolidated overarching safety management provisions from six existing Annexes | Four components: safety policy, safety risk management, safety assurance, safety promotion |
| Who is covered | Amendment 1 (2nd edition; adopted 2 March 2016, applicable 7 November 2019) extended SMS to organisations responsible for type design or manufacture of engines and propellers | Part 119 certificate holders and applicants for Part 121 and Part 135 operations; Letter of Authorization holders under 91.147 (air tours); holders of both a type certificate and production certificate under Part 21 |
| Latest change | Amendment 2 adopted 23 June 2025, effective 4 November 2025, applicable 26 November 2026; it concerns SMS for certified RPAS operators in international operations, their approved maintenance organisations and certified heliports | SMS must be scaled to organisation size, scope and complexity (5.5) |
Where it matters for research
Aerospace researchers and test organisations meet these terms in hazard analyses, safety cases and incident reporting. The vocabulary above gives a common baseline: describe the system, identify hazards, assess severity and likelihood, control the risk, then verify that the controls work. For voluntary reporting, see our guide to NASA’s Aviation Safety Reporting System; for the FAA’s research facility, see the FAA William J. Hughes Technical Center. Analysis methods that transfer include root cause analysis and the critical incident technique. For the wider field see what aerospace engineering is and human factors engineering.
Common misunderstandings
- A hazard is not a risk. The rule text separates the condition (hazard) from the composite of severity and likelihood (risk).
- An SMS is not one size fits all. Part 5 requires it to be appropriate to the organisation’s size, scope and complexity.
- Annex 19 did not invent safety management. Its first edition consolidated provisions that already sat in six Annexes.
- Part 5 does not cover every aviation business. It names specific certificate holders and applicants.
FAQ
What does aviation safety mean?
It is the management of risk so that aircraft accidents and incidents are prevented, organised today through safety management systems and State safety programmes.
What are the four components of an SMS?
Safety policy, safety risk management, safety assurance and safety promotion (14 CFR 5.5).
Who must have an SMS in the United States?
Under 14 CFR 5.1: Part 119 certificate holders and applicants for Part 121 and Part 135 operations, air tour operators holding a 91.147 Letter of Authorization, and holders of both a type certificate and production certificate under Part 21, plus related licensee and applicant cases.
What is ICAO Annex 19?
The ICAO Annex on safety management, first applicable on 14 November 2013, which consolidated safety management provisions from six earlier Annexes.
Sources
- eCFR, 14 CFR Part 5, Safety Management Systems: ecfr.gov/current/title-14/part-5 (read 2026-11-08).
- ICAO, Safety Management Standards and Recommended Practices (Annex 19): icao.int/safety-management (read 2026-11-08).
