14 CFR 23.173 - Static longitudinal stability.

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.

This action proposes special conditions for the Tamarack Aerospace Group's modification to the Cirrus Model 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 proposed 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.

These special conditions are issued for the XtremeAir GmbH XA42 airplane. The XA42 airplane has a novel or unusual design feature associated with its static stability. This airplane can perform at the highest level of aerobatic competition. To be competitive, the aircraft was designed with positive and, at some points, neutral stability within its flight envelope. Its lateral and directional axes are also decoupled from each other providing more precise maneuvering. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for these design features. 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. These special conditions are only applicable to aircraft certified solely in the acrobatic category.

These special conditions are issued for the installation of an inflatable three-point restraint safety belt with an integrated airbag device at the aft position in two-place side-facing divan seats on the Embraer S.A. aircraft model EMB-505. These airplanes, as modified by the installation of these inflatable safety belts, will have novel and unusual design features associated with the upper-torso restraint portions of the three-point safety belts, which contain an integrated airbag device. 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.