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:
During the period 2001/2002, skin cracking was found adjacent to the butt joint forward of frame 19 * * *. The cracks emanated from chemically-etched pockets on the internal surface of the skin. * * * [C]racking in multiple adjacent bays * * * could compromise the structural integrity of the fuselage in the event that the multiple cracks joined into a single crack. * * *
During 2008, a further report was received at BAE Systems of a 13.78 inch crack in an AVRO 146-RJ that occurred 514 flight cycles (FC) short of the next 4 000-FC repetitive inspection interval.* * *
* * * * ** *
The proposed ADwould require actions that are intended to address the unsafe condition described in the MCAI.