Special Conditions: Airbus Model A350-900 Series Airplane; Composite Fuselage In-Flight Fire/Flammability Resistance

These special conditions are issued for Airbus Model A350-900 series airplanes. These airplanes will have a novel or unusual design feature associated with the in-flight fire and flammability resistance of the composite fuselage. Experience has shown that eliminating fire propagation on the surface of interior and insulating materials enhances survivability since the threats from an in-flight fire (e.g., toxic gas emission and smoke obscuration) are typically by-products of a propagating fire. The Airbus Model A350-900 series airplanes must provide protection against an in-flight fire propagating along the surface of the fuselage. Special conditions are needed to address this design feature. 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.