This specification provides designers and manufacturers of electric propulsion for light sport aircraft design references and criteria to use in designing and manufacturing EPUs.

Declaration of compliance is based on testing and documentation during the design, ground testing and flight testing of the EPU by the manufacturer or under the manufacturers’ guidance.

Manufacturers of the EPUs are encouraged to review and incorporate appropriate standards and lessons learned from ground based systems as documented in SAE J2344 and EASA CRI F-58 (see Appendix X2).

Electric aircraft may contain potentially hazardous level of electrical voltage or current. It is important to protect persons from exposure to this hazard. Under normal operating conditions, adequate electrical isolation is achieved through physical separation means such as the use of insulated wire, enclosures, or other barriers to direct contact. There are conditions or events that can occur outside normal operation that can cause this protection to be degraded. Some means should be provided to detect degraded isolation or ground fault. In addition, processes or hardware, or both, should be provided to allow for controlled access to the high voltage system for maintenance or repair. A number of alternative means may be used to achieve these electrical safety goals including automatic hazardous voltage disconnects, manual disconnects, interlock systems, special tools and grounding. The intention of all these means is either to prevent inadvertent contact with hazardous voltages or to prevent damage or injury from the uncontrolled release of electric energy. Lightning strikes are not addressed in this Standard Practice because LSA aircraft are limited to VMC flight only.

1.1 This specification covers minimum requirements for the design and manufacture of Electric Propulsion Units (EPU) for light sport aircraft, VFR use. The EPU shall as a minimum consist of the electric motor, associated controllers, disconnects and wiring, an Energy Storage Device (ESD) such as a battery or capacitor, or both, and EPU monitoring gauges and meters. Optional onboard charging devices, in-flight charging devices or other technology may be included.

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.