Patent ID: 7331421

Claim:
An aircraft inlet system, comprising: an inlet flow surface having multiple openings; an acoustic treatment positioned adjacent to the inlet flow surface, the acoustic treatment having multiple cells in fluid communication with the openings in the inlet flow surface; and a fluid collector passage positioned to collect liquid entering the acoustic treatment through the multiple openings, the fluid collector passage having an exit aperture through which the liquid drains, the fluid collector passage including at least one flow restrictor positioned to at least restrict a flow of air from the exit aperture through the fluid collector passage to the multiple openings, wherein at least a portion of the flow restrictor is changeable between a first configuration in which the flow of air is restricted at a first level and a second configuration in the which the flow of air is unrestricted or restricted at a second level less than the first level in response to a change in a pressure difference between the inlet flow surface and the exit aperture.