Summary
We propose to adopt a new airworthiness directive (AD) for the products listed above that would supersede an existing AD. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:
DGAC [Direction Generale de l'Aviation Civile] France issued AD F-2005-078 [which corresponds to FAA AD 2006-02-06] to require the modification (Airbus modification 13023), defined in Airbus SB [service bulletin] A310-53-2124, to increase the service life of junctions of center box upper frame bases to upper fuselage arches. This structural modification falls within the scope of the work related to the extension of the service life of A310 aircraft and widespread fatigue damage evaluations. The threshold timescales for accomplishment of the tasks as defined in SB A310-53-2124 were refined and reduced. ** * * * * * *
The unsafe condition is fatigue cracking of the frame foot run- outs, which could lead to rupture of the frame foot and cracking in adjacent frames and skin, and which could result in reduced structural integrity of the fuselage. The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.