Introduction to the standard specification for the Standard Specification for Aircraft Electric Propulsion Systems, ASTM F3239-22a
Instructional Goal
The goal of the two lesson modules is to increase student knowledge of the relationship between electric or hybrid-electric aircraft propulsion technologies and the applicable standards related to design and airworthiness. This module focuses on airworthiness requirements for aircraft electric propulsion systems. The companion website is divided into three areas: Materials, Assessments, and Resources. There are three informational videos in the Materials section of the companion website: Introduction to Airworthiness, Terminology in ASTM F3239, and Requirements in ASTM F3239. The Assessments section of the website contains multiple choice assessments and answer keys for each of the four videos in the Materials section. Please check for updated versions of this standard and for associated changes.
There are two goals for the students in this module:
- Locate the applicable airworthiness requirements reference standards for the following systems of an electric propulsion engine.
- Energy distribution
- Control and indication
- Hazard mitigation
- Powerplant installation
- Determine connections to FAA regulations in Title 14 Code of Federal Regulations Part 23 and FAA Advisory Circulars.
Learning Standards
N/A
Performance Objectives
- Given a list of systems, the student shall correctly identify which airworthiness requirements are located in ASTM F3239.
- Given a particular system, the student shall correctly identify the appropriate airworthiness requirements required in the ASTM F3239 or other standards.
- Given a list of terms, the student shall correctly identify the appropriate definition.
Instructional Resources
- Access to FAA and ASTM documentation.
- ASTM F3239 Standard Specification for Aircraft Electric Propulsion Systems
- FAA Title 14 CFR Part 23 AIRWORTHINESS STANDARDS: NORMAL CATEGORY AIRPLANES
- FAA Title 14 CFR Part 33 AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES
- FAA Title 14 CFR Part 35 AIRWORTHINESS STANDARDS: PROPELLERS
- ASTM F3060 Standard Terminology for Aircraft
Student Characteristics
Post-secondary adults with an interest in aircraft.
Delivery Method
Online or in-person
Lesson Outline
Introduction
The purpose of this module is to familiarize students with available industry standards related to the airworthiness of aircraft electric propulsion systems. The student will be provided with multiple resources such as videos, assessments, and activities. The videos are an introduction and do not replace in-depth study of the standards or regulations. The videos should be previewed by the instructor to determine how the video may be used in one of more classes. Depending on the course objectives, these materials may be adjusted to fit the needs of courses in technical, engineering, and general science or design courses.
Content
See the associated website for instructional videos, assessments, and activities. The transcription for each of the videos is on the website in the Materials section. By clicking on each of the videos, the viewer may select from three options of video and transcript.
Closing
This module introduces the student to the use of standards for the airworthiness of aircraft electric propulsion systems. It is not a comprehensive module on the airworthiness process, airworthiness requirements, or aircraft certification.
Assignments/Activities
These are sample ideas for student activities and assignments that may be completed in class or as homework, and either by one student or in groups. The activities are not designed to be appropriate for all courses at all levels. Based on the instructional level and goals of the course, the instructor may choose to modify these activities or develop their own.
- A. Create a table of electric aircraft in certification or development, including engine type, country of origin, and citations.
- B. List current and projected uses of electric aircraft using cited sources in table format.
C. Compare and contrast the following pairs:
- Electric engine vs. electric propulsion system
- Energy distribution systems vs. energy storage system
- Capacity vs. usable energy capacity
- Hazard identification vs. hazard mitigation
Use a comparison table with definitions and examples.
- D. Define “airworthy,” “airworthiness,” and “certificated” using 14 CFR and FAA videos. Investigate FAA certification process.
- E. Reflect on electric propulsion: Is it always best for people/cargo transport? Justify with multiple sources.
- F. Explore what Title 14 CFR covers, define “Federal Regulation,” and explain their significance.
- G. Investigate propeller placement and types on certified electric aircraft in various countries. Define “pusher” vs. “puller.”
After viewing the videos and completing some activities, students should generate a list of lingering questions about electric propulsion. Instructors may collect and use these to connect with other course content.
Assessment
See the four sets of assessment questions on the website. Any one of the assignments may be an option for a summative assessment.
Answer Key
1. Introduction to Airworthiness Requirements for Electric Propulsion
- Q1: What is one major reason flying on commercial airlines continues to be safe?
B. Commitment to standard construction and maintenance procedures - Q2: What does the ASTM F3239 standard specifically address?
A. Airworthiness requirements for electric and hybrid-electric propulsion systems - Q3: Which organization certifies civilian aircraft in the United States?
B. Federal Aviation Administration (FAA) - Q4: Which category of civilian aviation is specifically linked to FAA Title 14 CFR Part 23?
B. General aviation - Q5: How do industry standards relate to FAA oversight?
A. They support compatibility and standardization but do not replace FAA oversight - Q6: What kind of documents does the FAA publish to guide airworthiness beyond regulations?
C. Advisory circulars, airworthiness directives, and service bulletins - Q7: What role do consensus standards play in aviation certification?
A. They provide additional guidance to complement FAA regulations - Q8: Who governs the FAA?
B. U.S. Department of Transportation - Q9: What is one key benefit of using industry standards in aviation?
C. They help maintain high safety standards through uniform procedures - Q10: Why might students be advised to ask their instructor about state aviation laws?
A. Because aviation regulation may vary across U.S. states
2. Terminology in ASTM F3239
- Q1: What are the first three sections typically found in ASTM standards?
A. Scope, Referenced Documents, Terminology - Q2: Which standard contains comprehensive definitions for airworthiness-related terms?
B. ASTM F3060 - Q3: What is the main function of an electric engine within the propulsion system?
B. Provide thrust for propulsion - Q4: Which of the following is NOT explicitly listed as a component of an electric propulsion system in ASTM F3239?
C. Avionics system - Q5: Why is standardized terminology important in the aviation industry?
B. It facilitates communication with clarity and precision - Q6: What component in an electric propulsion system is equivalent to a fuel tank in a gasoline-based system?
C. Energy Storage System (ESS) - Q7: Which of the following best defines the Energy Distribution System (EDS) in electric propulsion?
A. It delivers energy from the source to the electric engine - Q8: What issue is highlighted by the term “quantity” in the context of standardized definitions?
C. Inconsistent interpretation of what and when to measure - Q9: What is the practical reason battery manufacturers restrict full access to usable energy capacity?
A. To prolong battery life - Q10: How are “capacity” and “usable energy capacity” different in electric propulsion systems?
B. Usable energy capacity is a subset limited by design
3. Requirements in ASTM F3239
- Q1: What is one reason why ASTM F3239 includes references to other standards in the powerplant installation section?
B. To build on existing requirements without duplicating details - Q2: In both gasoline and electric propulsion systems, what is a shared requirement for the oil system?
C. It must be independent and maintain a safe operating temperature - Q3: What condition must the energy distribution system be able to support to meet F3239 requirements?
B. Maximum continuous power for at least 30 minutes - Q4: Why must multiple electric engines have independent energy distribution systems?
A. To maintain redundancy and safety during operation - Q5: According to the video, what determines where energy system independence begins and ends?
A. Guidance provided in FAA advisory circulars - Q6: What types of systems are discussed in the hazard mitigation section of the standard?
C. Protection against fire, lightning, and ice - Q7: Why is it important to define what the pilot can replace in energy storage systems?
C. It ensures pilot actions don’t compromise system safety - Q8: What does the video emphasize about the similarity of requirements between gasoline and electric systems?
B. Many core requirements remain the same despite the energy source - Q9: Why does the video compare standards to “puzzle pieces”?
A. Each contributes to a complete system of aviation safety - Q10: What is one key takeaway the video wants learners to leave with?
C. A working knowledge of standards improves aviation safety awareness