ISO 21895:2026

International
Standard
ISO 21895
Second edition
Categorization and classification of
2026-09
civil uncrewed aircraft systems
Catégorisation et classification des aéronefs civils sans pilote
Reference number
© ISO 2026
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Risk-based categorization of UAS operations . 2
5 Classification and grading principle . . 3
6 Classification . 5
6.1 UA-configuration .5
6.2 Mode of launch and recovery or take-off and landing .5
6.2.1 Mode of launch or take-off .5
6.2.2 Mode of recovery or landing .5
6.3 Engine or powerplant type and energy source .6
6.3.1 Engine or powerplant type .6
6.3.2 Energy source .6
6.4 Control mode .6
6.5 Maximum achievable height .7
6.6 Maximum airspeed .7
6.7 Flight endurance .7
6.8 C2-link coverage .7
6.9 Kinetic energy .8
6.10 Identification mode .8
7 UAS classes . 8
Bibliography .11

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
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This document was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles, Subcommittee
SC 16, Uncrewed aircraft system.
This second edition cancels and replaces the first edition (ISO 21895:2020), which has been technically
revised.
The main changes are as follows:
— Introduction of risk-based taxonomy of UAS Operations. The proposed risk-based taxonomy of UAS
operations is aligned with the Foreword of Part IV (International operations of RPAS) of Annex 6
(Operations of Aircraft) to the Chicago Convention.
— Introduction of UAS classes. The proposed UAS classes are harmonized with relevant aviation authorities
around the world and already largely used by UAS manufacturers in more than one continent.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
This document sets out a methodology for the multi-dimensional classification of uncrewed aircraft system
(UAS) and related risk-based taxonomy of UAS operations. The purpose of this classification model is not
to replace any existing regulatory model but to provide a more granular classification tool for those who
need to approach the classification of UAS from their own perspective and for whom the regulatory model is
too broad. Examples include but are not limited to engineers, manufacturers, certification bodies, insurance
underwriters or accident investigators.
Risk-based categorization of UAS operations is inspired by ICAO guidance, which is applicable world-wide.
For taxonomies of domains beyond UAS and their operations, readers can refer to documents cited in the
Bibliography, for levels of automation, vertiports and UTM services.

v
International Standard ISO 21895:2026(en)
Categorization and classification of civil uncrewed aircraft
systems
1 Scope
This document specifies requirements for the classification and grading of civil uncrewed aircraft systems
(UAS). This document applies to heavier-than-air aircraft as well as aerostats of any possible architecture.
This document applies to the industrial conception, development, design, production and delivery of civil
UAS. It also applies to operations, modification, repair and maintenance of civil UAS.
NOTE The characteristics in this document can be used individually or in combination, to meet specific needs of
the classification and grading of civil UAS.
This document does not apply to taxonomies of:
a) automation levels;
b) vertiports;
c) UTM services.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 21384-4, Uncrewed aircraft systems — Part 4: Vocabulary
ISO 23629-8, UAS traffic management (UTM) — Part 8: Remote identification
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 21384-4 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
multicopter
rotorcraft lifted by more than two power driven rotors on substantially vertical axis
3.2
aerostat
lighter-than-air aircraft
Note 1 to entry: Aerostats can be power-driven (i.e. airships) or non-power-driven (i.e. aerostatic balloons).

4 Risk-based categorization of UAS operations
In several jurisdictions, the operation of UAS is regulated in proportion to the safety risk perceived by the
society in relation to the intended operation.
Such a categorization scheme is independent from the nature (e.g. recreational, professional non-commercial
or commercial) of the operation and from the type of application (e.g. survey, collecting imagery, aerial work,
transport, agriculture).
UAS operations shall be classified in accordance with Table 1.
Table 1 — Risk-based categorization of UAS operations
Category Main features Subdivisions Conditions
Precise limitations [typ- Fly permanently over
ically visual line-of-sight people
A0
(VLOS) and height] estab-
UA class C0
lished by the regulatory
Fly shortly over people
authority.
A1
UA class C1
Limited competence of
Fly close to people (i.e.
remote pilot.
urban areas)
A2
Airworthiness verified
Open (low risk perceived by
UA class C2
through industry processes.
society)
No authorisation by regula-
tory authority required.
Commercial and non-com- Fly far from people (e.g.
mercial (including recrea- above sea or rural areas)
A3
tional) operations possible.
UA classes C3, C4, C5, C6
Possible registration to en-
sure security and privacy.
Demonst
...