ISO 21895:2020

Categorization and classification of civil unmanned aircraft systems

This document specifies requirements for the classification and grading of civil unmanned aircraft system (UAS). This document applies to heavier than air aircraft as well as lighter than air aircraft of any possible architecture. This document applies to the industrial conception, development, design, production and delivery of civil UAS. It also applies to modification, repair and maintenance of civil UAS. The characteristics in this document can be used individually or in combination, to meet specific needs of the classification and grading of civil UAS. Risk-based categorization of UAS operations is prerogative of the aviation authorities and it is hence out of scope of this document.

Catégorisation et classification des aéronefs civils sans pilote

General Information

• Status: Published
• Publication Date: 06-Feb-2020
• 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: 9092 - International Standard to be revised
• Start Date: 28-Nov-2024
• Completion Date: 13-Dec-2025

Overview

ISO 21895:2020 - Categorization and classification of civil unmanned aircraft systems - provides a multi-dimensional framework for classifying and grading civil UAS (unmanned aircraft systems). Applicable to both heavier‑than‑air and lighter‑than‑air architectures, the standard supports industrial activities across conception, design, production, delivery, modification, repair and maintenance. ISO 21895 is a technical tool for stakeholders who need more granular UAS classification than regulatory operational categories; note that risk‑based operational categorization remains the prerogative of aviation authorities and is out of scope.

Key topics and technical requirements

ISO 21895 defines structured classification axes and grading rules. Major topics include:

• UA‑configuration: fixed‑wing, glider, single‑rotor helicopter, multicopter, gyroplane, VTOL, aerostats, ornithopters and others.
• Launch and recovery / take‑off & landing modes: horizontal rollout, vertical, catapult/ejection, tether release, manual launch, parachute, net recovery, etc.
• Engine / powerplant and energy source: piston, turbine, electric, rocket, mixed powerplants; liquid, gaseous fuels, batteries, solar and hybrid energy sources.
• Control mode: manual (human in the loop), automatic (human on the loop), autonomous (human out of the loop); control mode can vary by flight phase.
• Performance levels:
  • Maximum achievable height (levels I–V from ≤15 m up to >18 300 m)
  • Maximum airspeed (levels defined in km/h and Mach ranges)
  • Flight endurance (from ≤0.5 h up to >24 h)
  • C2‑link coverage (operating radius categories up to >200 km)
  • Kinetic energy categories (levels I–V); kinetic energy calculated by the standard E = 1/2 m V^2 (with a specified equivalent multiplier for fixed‑wing V)
• Identification mode: unregistered, fixed label, electronic UAS ID, ATC transponder/ADS‑B capability.
• Grading by maximum take‑off mass: Levels I–VI (example ranges from ≤0.25 kg up to >150 kg).

Applications and who uses it

ISO 21895 is valuable for:

• Manufacturers and designers needing consistent classification for product development and compliance planning.
• Certification bodies and testing laboratories that require objective grading criteria for performance and safety assessment.
• Insurance underwriters and risk analysts to refine exposure models based on kinetic energy, mass and control modes.
• Accident investigators and maintenance organizations for post‑incident analysis and component grading.
• System integrators and procurement teams evaluating UAS variants by capability and operational envelope.

Keywords: ISO 21895, UAS classification, drone classification, unmanned aircraft systems, UAS grading, civil UAS standards, UAS certification.

Related standards

• Normative reference: ISO 21384‑4 (Unmanned aircraft systems - Part 4: Vocabulary) - used for terminology consistency.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 21895
First edition
2020-02
Categorization and classification of
civil unmanned aircraft systems
Catégorisation et classification des aéronefs civils sans pilote
Reference number
©
ISO 2020
© ISO 2020
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]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification and grading principle . 1
5 Classification . 3
5.1 UA-configuration . 3
5.2 Mode of launch and recovery/take-off and landing . 4
5.2.1 Mode of launch/take-off . 4
5.2.2 Mode of recovery/landing . 4
5.3 Engine/powerplant type and energy source . 4
5.3.1 Engine/powerplant type . 4
5.3.2 Energy source . 5
5.4 Control mode . 5
5.5 Maximum achievable height . 5
5.6 Maximum airspeed . 5
5.7 Flight endurance . 6
5.8 C2-link coverage . 6
5.9 Kinetic energy . 6
5.10 Identification mode . 7
6 Grading . 7
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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
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, Unmanned aircraft systems.
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 © ISO 2020 – All rights reserved

Introduction
This document sets out a methodology for the multi-dimensional classification of unmanned aircraft
system (UAS). The purpose of this classification model is not to replace any existing regulatory model
but to provide a more granular classification tool for use by those who need to approach the classification
of UAS from their own perspective and for whom the regulatory model is too broad. Examples may
be but are not limited to; engineers, manufacturers, certification bodies, insurance underwriters or
accident investigators.
INTERNATIONAL STANDARD ISO 21895:2020(E)
Categorization and classification of civil unmanned
aircraft systems
1 Scope
This document specifies requirements for the classification and grading of civil unmanned aircraft
system (UAS). This document applies to heavier than air aircraft as well as lighter than air aircraft of
any possible arch
...