Special Conditions: Viking Air, Ltd., Models DHC-6-100/-200/-300; Avmax Aviation Services, Inc., Installation of Rechargeable Lithium Batteries

These special conditions are issued for the Viking Air, Ltd., models DHC-6-100/-200/-300, Twin Otter, Turbopropeller airplanes. This airplane, as modified by Avmax Aviation Services, Inc., will have a novel or unusual design feature associated with the use of a replacement option of a lithium battery instead of nickel-cadmium and lead-acid rechargeable 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.