Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Airbus Model A300 F4-600R series airplanes and Model A300 C4-605R Variant F airplanes. This proposed AD would require modifying certain structure in the fuselage zone at the lavatory venturi installation in the nose section, and performing a related investigative action and corrective action if necessary. This proposed AD results from an analysis that revealed that airplanes equipped with Airbus Modification 08909 had a concentration of loads higher than expected in the fuselage zone (high stress) at the lavatory venturi installation in the nose section, which could be the origin of cracks that developed in the fuselage skin and propagated from the edge of the air vent hole. We are proposing this AD to prevent fatigue cracking of the fuselage skin, which could result in loss of the structural integrity of the fuselage and consequent rapid depressurization of the airplane.