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:
While they were gaining access to the THS (trimmable horizontal stabilizer) fuel tank for maintenance check, several operators have found one or several of the 8 THS hoist point fitting bases cracked or broken-off. The breakage resulted in metallic debris being released within the Trim Tank. The origin of the damage is most probably due to interference with the THS hoisting lugs that are stowed in the hoist point fittings in the reverse position, being screwed too deep inside the THS hoist fittings. Damaged hoist point fittings could cause the release of metallic debris within the THS fuel system.
* * * Compliance with the requirementsof this AD will also eliminate potential contributing factor[s] to ignition risks.
The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.