Summary
We are revising an earlier NPRM for the products listed above. This action revises the earlier NPRM by expanding the scope. 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:
During maintenance on one aircraft, it was discovered that the overpressure capsules were broken on both pressurization valves. Failure of the pressurization control regulating valve (overpressure capsule) will affect the aircraft's overpressure protection * * *. * * * * * The unsafe condition is overpressurization, which can result in injury to the occupants and possible structural failure leading to loss of control of the airplane. The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.