Special Conditions: Tamarack Aerospace Group, Cirrus Model SR22; Active Technology Load Alleviation System (ATLAS)

These special conditions are issued for the Tamarack Aerospace Group's modification to the Cirrus SR22 airplane. This airplane as modified by Tamarack will have a novel or unusual design feature(s) associated with Tamarack Aerospace Group's modification. The design change will install winglets and an Active Technology Load Alleviation system (ATLAS). The addition of the ATLAS mitigates the negative effects of the winglets by effectively aerodynamically turning off the winglet under limit gust and maneuver loads. This is accomplished by measuring the aircraft loading and moving a small aileron-like device called a Tamarack Active Control Surface (TACS). The TACS movement reduces lift at the tip of the wing, resulting in the wing center of pressure moving inboard, thus reducing bending stresses along the wing span. 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.