US Patent 11434018 Switchable air inlet device for engine air

An air inlet device for an air inlet of an aircraft. The air inlet device has air guide arrangements. An air guide arrangement has an inlet plate, an outlet plate, and pivot plates arranged therebetween. The outlet plate and the pivot plates can be rotated about a central axis of the air inlet device by adjustment rings, so that the air guide arrangement is transitioned from a linear state to a curved state, and vice versa. The air inlet device allows for selective switching between a state with low radar signature and a state with high performance of an engine.