Special Conditions: Airbus Model A350-900 Series Airplane; Tire Failure--Debris Penetration or Rupture of Fuel-Tank Structure

These special conditions are issued for Airbus Model A350-900 series airplanes. These airplanes will have a novel or unusual design feature associated with fuel tanks constructed of carbon-fiber reinforced plastic (CFRP) materials located within the tire-impact zone, including the wing fuel tanks. The ability of aluminum wing skins, as has been conventionally used, to resist penetration or rupture when impacted by tire debris, is understood from extensive experience. The ability of carbon-fiber composite material to resist these hazards has not been established. No current airworthiness standards specifically address this hazard for all exposed wing surfaces. 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.