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:
This [Brazilian] AD results from reports of cracking in the firewall of the auxiliary power unit (APU). This AD is being issued to detect and correct this cracking, which could result in reduced structural integrity of the fuselage and empennage in the event that a fire penetrates through the firewall of the APU.
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The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.