The FAA has issued an NPRM for a new airworthiness directive for the Embraer Phenom 300 that would supersede AD 2013-22-20. The proposed AD describes the unsafe condition as cracks beyond acceptable limits in the carbon discs of the left and right brake assemblies. It requires an inspection to determine if the airplane has the affected part number brake assembly installed and an inspection for cracks of the affected brake assembly, with repair or replacement as necessary. The FAA is taking comments until August 4.