Special Conditions: Cessna Aircraft Company, Model 525C (CJ4); Lithium Ion Battery Installation

These special conditions are issued for the Cessna Aircraft Company, model 525C (CJ4) airplane. This airplane will have a novel or unusual design feature(s) associated with the installation of lithium ion (Li-ion) batteries. Cessna Aircraft Company proposes to use a lithium-ion main battery on the new model 525C (CJ4) commuter category airplane for main battery applications, and is also considering the use of this technology in several other auxiliary battery applications in this airplane. This type of battery possesses certain failure, operational characteristics, and maintenance requirements that differ significantly from that of the nickel cadmium and lead acid rechargeable batteries currently approved in other normal, utility, acrobatic, and commuter category airplanes. 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.