Special Conditions: Blackhawk Aerospace Technologies, Textron Model 500 Series Airplanes; Rechargeable Lithium Batteries and Battery System Installations

These special conditions are issued for the Textron Model 500/ 550/S550/560/560XL/560XLS airplanes. These airplanes, as modified by Blackhawk Aerospace Technologies (Blackhawk), 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 electronic GI 275 Standby Instruments containing rechargeable lithium-ion batteries. 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.