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:
Following the rupture of an alternator and vapour cycle cooling system pulley drive assembly, the AD 2008-0067-E was published to require the replacement of the pulley drive assembly by a new one of an improved design.
Later on, cases of rupture of the alternator and vapour cycle cooling system compressor drive shaft and of cracks on the standby- alternator and compressor support were reportedly found.
Such failures could lead to the loss of the alternator and of the vapour cycle cooling systems, and could also cause mechanical damage inside the power plant compartment.
To address this condition, the AD 2008-0129-E superseded AD 2008-0067-E and mandates the removal, as a temporary measure, of the compressor drive belt and of the torque limiter, the conditional replacement of the pulley drive shear shaft, and repetitive inspections for cracks of the pulley drive assembly and of the alternator/compressor support.
The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.