ASTM F3338-24 PDF

Full title and description

ASTM F3338-24 — Standard Specification for Design of Electric Engines for General Aviation Aircraft. This specification establishes minimum design requirements, certification-oriented test requirements, and application guidance for electric engines intended for use on general aviation aircraft, including notes on distributed propulsion, hybrid arrangements, and integration considerations with propellers or fans.

Abstract

ASTM F3338-24 provides manufacturers, designers, and certification applicants with a baseline specification for electric engine design in general aviation. The standard covers design principles, recommended tests (endurance, vibration, over‑torque, over‑temperature and representative-load shaft tests), considerations for distributed propulsion and hybrid configurations, and guidance to coordinate with civil aviation authorities for certification. It is intended to be used alongside applicable airworthiness regulations and complementary technical standards.

General information

• Status: Active.
• Publication date: 15 September 2024.
• Publisher: ASTM International.
• ICS / categories: 49.050 (Aerospace engines and propulsion systems).
• Edition / version: F3338-24 (2024).
• Number of pages: 14.

Basic bibliographic details and status as published by ASTM International. DOI assigned: 10.1520/F3338-24.

Scope

This specification covers minimum requirements for the design of electric engines for general aviation aircraft. It addresses: core mechanical, thermal and electrical design considerations; representative test requirements for demonstrating endurance and safe operation; treatment of distributed propulsion arrangements (with note that additional requirements may be needed); and use of the specification alongside supplementary requirements for gearboxes, thrusters, and energy storage when applicable. Applicants are advised to coordinate use of this specification with their civil aviation authority. Units are stated in inch‑pound with SI conversions for information.

Key topics and requirements

• Minimum design requirements for electric engines (mechanical, electrical, thermal, structural).
• Certification-oriented tests: endurance/durability, vibration, over‑torque, over‑temperature, and representative-load shaft testing.
• Guidance for distributed propulsion and how common motor controllers, harness segregation, cooling, and power supplies affect design and verification.
• Notes on hybrid configurations and use of supplemental requirements where combustion engines or thrusters are combined with electric engines.
• Recommendation to coordinate with Civil Aviation Authorities for acceptance and to reference applicable airworthiness regulations.

Typical use and users

Used by electric propulsion system designers, aircraft and engine OEMs, certification and compliance engineers, testing laboratories, and regulatory authorities reviewing means of compliance for airworthiness. Also referenced by university and research programs working on aircraft electric propulsion. It is applied during design, verification testing, certification planning, and supplier requirements development.

Related standards

Commonly used alongside national airworthiness regulations (for example, Title 14 CFR Part 23, Part 33, Part 35 in the U.S.), and other technical standards such as ASTM terminology and part standards, IEC 60034 (rotating electrical machines), IEC 60349 (electric traction rotating machines), and other ASTM aerospace specifications. Users should consult applicable FAA/CAA guidance and harmonize test and verification methods with local certification requirements.

Keywords

electric engine; electric propulsion; general aviation; distributed propulsion; endurance testing; vibration testing; over‑torque; over‑temperature; certification; airworthiness.

FAQ

Q: What is this standard?

A: ASTM F3338-24 is a Standard Specification that defines minimum design and verification requirements for electric engines intended for general aviation aircraft. It was published by ASTM International on 15 September 2024 and is currently active.

Q: What does it cover?

A: It covers mechanical, electrical and thermal design considerations, certification‑oriented test requirements (including endurance, vibration, over‑torque, and over‑temperature tests), and guidance for distributed propulsion and hybrid arrangements. It does not by itself replace any airworthiness regulation and should be used together with the relevant civil aviation authority requirements.

Q: Who typically uses it?

A: Propulsion and aircraft manufacturers, certification engineers, testing labs, regulators, and research organizations developing or certifying electric engines for general aviation applications.

Q: Is it current or superseded?

A: As published, F3338-24 is the 2024 edition and is listed as active. Users should check ASTM or their national SDO records for any amendments or newer revisions after 15 September 2024.

Q: Is it part of a series?

A: The specification was developed under ASTM Committee F39 (aircraft and aerospace propulsion systems) and is intended to be used alongside related ASTM and industry standards and guidance documents; it is complementary to airworthiness regulations rather than a sequential series standard.

Q: What are the key keywords?

A: Electric engine, general aviation, distributed propulsion, endurance testing, vibration, over‑torque, over‑temperature, certification, airworthiness.