REDUCING OBSTRUCTION

An apparatus for reducing obstruction compromising operation of at least one sensor having a portion disposed through skin of a vehicle, the portion having a surface offset from the skin comprises a member disposed offset from the surface. The member includes a first side having an inner surface and an outer surface that opposes the surface of the portion, and a second side having a second side inner surface and a second side outer surface. The second side outer surface faces exterior of the vehicle. A space is disposed between the second side inner surface and the inner surface. Ports are pneumatically connected with the space, a source of compressed air and a vent.