Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Airbus Model A319, A320, and A321 series airplanes. This proposed AD would require replacing the cargo ventilation extraction duct at frame 65 with a new duct, and relocating the temperature sensor in the aft cargo compartment. This proposed AD is prompted by a report indicating that, during a test of the fire extinguishing system, air leakage around the temperature sensor for the aft cargo compartment reduced the concentration of fire extinguishing agent to below the level required to suppress a fire. We are proposing this AD to prevent air leakage around the temperature sensor for the aft cargo compartment, which, in the event of a fire in the aft cargo compartment, could result in an insufficient concentration of fire extinguishing agent, and consequent inability of the fire extinguishing system to suppress the fire.