ISO 21895:2026

• Abstract:

  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: automation levels; vertiports; UTM services.

• Status: Published
• Publication Date: 17-Sep-2026
• ICS: 49.020 - Aircraft and space vehicles in general
• Technical Committee: ISO/TC 20/SC 16 - Unmanned aircraft systems
• Drafting Committee: ISO/TC 20/SC 16/WG 1 - General
• Current Stage: 6060 - International Standard published
• Start Date: 18-Sep-2026
• Due Date: 28-Nov-2026
• Completion Date: 18-Sep-2026

• Revises: ISO 21895:2020 - Categorization and classification of civil unmanned aircraft systems
• Effective Date: 07-Jan-2025

ISO 21895:2026 is an International Standard from ISO for categorizing and classifying civil uncrewed aircraft systems (UAS). ISO 21895:2026 specifies a multi-dimensional classification and grading method for civil UAS, including a risk-based way to sort operations and a class system for the aircraft itself. Engineers, manufacturers, certification bodies, insurers, and accident investigators can use it to describe a UAS from the viewpoint that matters for their work.

What does ISO 21895:2026 specify?

ISO 21895:2026 specifies requirements for the classification and grading of civil UAS. It covers heavier-than-air aircraft and aerostats of any architecture, and it applies across conception, development, design, production, delivery, operation, modification, repair, and maintenance.

The document is organized into scope, normative references, terms and definitions, risk-based categorization of UAS operations, a classification and grading principle, detailed classification criteria, and UAS classes. In practice, that means the standard first separates the operation by risk, then describes the aircraft by technical characteristics.

The scope also excludes taxonomies of automation levels, vertiports, and UTM services. That helps readers avoid using it as a general taxonomy for topics outside UAS and their operations.

What are the key requirements of ISO 21895:2026?

ISO 21895:2026 requires UAS to be classified from multiple viewpoints and then graded against a stakeholder-specific rule set. The main value is that the same aircraft can be described consistently for design, safety assessment, certification, or operational planning.

Risk-based categorization of UAS operations

ISO 21895:2026 groups operations into open, specific, and certified categories, with subtypes defined in Table 1. The open category covers A0 to A3, from tightly limited flights over people to flights far from people. In practice, this is the first step for deciding how much oversight, pilot competence, and operational control are needed.

The specific category is based on case-by-case conditions established by the regulatory authority and on the operator’s risk assessment. It includes operations such as BVLOS and EVLOS, so it matters when the mission is more complex than open-category use.

The certified category is split into Type #1 to Type #4. These cover operations such as international RPAS flights in controlled airspace under IFR, domestic transport of people or cargo through uncrewed VTOL capable aircraft, and high altitude operations. This section matters when the operation sits close to conventional aviation requirements.

Classification dimensions for the aircraft

ISO 21895:2026 classifies the UA by configuration, launch and recovery mode, engine or powerplant type, energy source, control mode, maximum achievable height, maximum airspeed, flight endurance, C2-link coverage, kinetic energy, and identification mode.

That means the standard is not limited to aircraft size. It also captures how the UA takes off and lands, how it is controlled, how far and how long it can fly, and how it can be identified. These are the factors that affect safety case writing, performance claims, and operational limits.

Clause 6.4 distinguishes manual, automatic, and autonomous control modes, and notes that the control mode can vary during flight phases. In practice, this helps a team state when a human is piloting, supervising, or absent from the control loop.

Clause 6.8 classifies C2-link coverage by operating radius, and notes that the highest level typically needs ground radio stations or satellite communication. That matters for beyond local-area operations and for communications planning.

Clause 6.9 gives a calculation method for flight impact kinetic energy. The resulting level helps relate aircraft mass and speed to the likely impact severity.

Clause 6.10 classifies identification mode from no registration-based identification through fixed labels, direct electronic remote identification in accordance with ISO 23629-8, network remote identification, transponder or ADS-B OUT capability, and ground-ground connection with traffic management units. This is important for traceability, traffic management integration, and surveillance.

UAS classes

ISO 21895:2026 grades UAS in Table 2 from C0 to C8 using maximum take-off mass and key features. Lower classes combine small mass with features such as electric propulsion, geofencing, and height limits. Higher classes add features such as flight termination system (FTS), geocaging, or design-dependent requirements.

C4 is limited to manual control mode, while C5 and C6 add FTS-related provisions. C2+ is identified separately and is noted as used by the World Trade Organisation (WTO) in relation to customs tariffs. For buyers and manufacturers, this table is the quickest way to map a platform to its class.

What terms does ISO 21895:2026 define?

ISO 21895:2026 defines multicopter as a rotorcraft lifted by more than two power-driven rotors on a substantially vertical axis. This term is useful when selecting the UA configuration in Clause 6.1.

ISO 21895:2026 defines aerostat as a lighter-than-air aircraft. The note adds that aerostats can be power-driven, such as airships, or non-power-driven, such as aerostatic balloons.

UAS means uncrewed aircraft system, the overall system described by the standard. UA means uncrewed aircraft, the aircraft element that is classified and graded.

VLOS means visual line-of-sight, BVLOS means beyond visual line-of-sight, and EVLOS means extended visual line-of-sight. These abbreviations identify operational cases in Table 1.

C2-link is the command-and-control link used to cover an operating radius in Clause 6.8. FTS means flight termination system, a safety feature named in the class definitions.

ADS-B OUT means automatic dependent surveillance - broadcast OUT capability. It is one of the identification modes in Clause 6.10.

Who uses ISO 21895:2026?

ISO 21895:2026 is used by engineers, manufacturers, certification bodies, insurance underwriters, accident investigators, and other stakeholders who need a finer classification than a broad regulatory model. It supports aircraft design, operational planning, product description, conformity assessment, and incident analysis.

The standard is also relevant to organizations involved in industrial conception, development, production, delivery, operation, modification, repair, and maintenance of civil UAS. In practice, it helps teams communicate the aircraft type, operating limits, and identification method in the same language.

What changed in ISO 21895:2026 from the previous edition?

ISO 21895:2026 cancels and replaces ISO 21895:2020 and is technically revised. The main changes are the introduction of a risk-based taxonomy of UAS operations, aligned with Part IV of Annex 6 to the Chicago Convention, and the introduction of UAS classes harmonized with relevant aviation authorities and already used by manufacturers on more than one continent.

Which standards are used with ISO 21895:2026?

ISO 21384-4, Uncrewed aircraft systems - Part 4: Vocabulary, supplies vocabulary used by the document. ISO 23629-8, UAS traffic management (UTM) - Part 8: Remote identification, supports the remote identification mode in Clause 6.10.

The text also points readers to ISO/SAE PAS 22736, ISO 5015-2, and ISO 23629-12 for other taxonomies, and it cites ICAO material, JARUS guidance, and the WTO HS Nomenclature in related contexts.

What does the ISO 21895:2026 document contain?

ISO 21895:2026 contains a risk-based operational taxonomy in Table 1, a class grading table in Table 2, and a classification framework shown in Figures 1 and 2. Clause 6 gives the detailed method for classifying configuration, launch and recovery, powerplant, energy source, control mode, height, speed, endurance, C2-link coverage, kinetic energy, and identification mode.

For readers, the document functions as a structured classification tool rather than a product test standard. It gives the categories, levels, and feature sets needed to describe a civil UAS in a technically consistent way.

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
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
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
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
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
...