Final rule · 2025-10180

Special Conditions: Delta Flight Products, Non-Rechargeable Lithium Batteries and Battery System Installations

These special conditions are issued for a supplemental type certificate (STC) to install non-rechargeable lithium batteries and battery systems on certain transport-category airplanes. These airplanes, as modified by Delta Flight Products, will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport-category airplanes. This design feature is non-rechargeable lithium batteries and battery system installed in emergency locator transmitters (ELTs). The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.