Summary
We propose to adopt a new airworthiness directive (AD) for the products listed above. 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:
* * * some structural areas have been identified for which existing recommended SB (service bulletin) needs to be rendered mandatory.
As a consequence, and because it has been shown that the torque applied to the tension bolts connecting the beam (stringer 49) to the forward and aft beam extension at FR11 and FR17 may be insufficient, this AD renders mandatory the replacement of those tension bolts, in order to limit the risks of damage or corrosion of the specified areas.
Damage or corrosion of the specified areas could result in reduced structural integrity of the airplane. The proposed AD would require actions that are intendedto address the unsafe condition described in the MCAI.