In one embodiment, a system includes an inlet grid configured to reduce distortion of an incoming airflow. The system may also include a vibration device coupled to the inlet grid and a controller communicatively coupled to the vibration device. The controller may transmit a vibration signal to the vibration device causing the vibration device to vibrate the inlet grid such that the inlet grid resonates at a natural frequency inducing a mode shape in the inlet grid. The mode shape may break up and prevent ice on the inlet grid.

In one embodiment, a system includes an inlet grid configured to reduce distortion of an incoming airflow. The system may also include a vibration device coupled to the inlet grid and a controller communicatively coupled to the vibration device. The controller may transmit a vibration signal to the vibration device causing the vibration device to vibrate the inlet grid such that the inlet grid resonates at a natural frequency inducing a mode shape in the inlet grid. The mode shape may break up and prevent ice on the inlet grid.

An ice protection system includes an aircraft surface and a gutter defined in the aircraft surface between raised rails. The gutter includes a mouth that narrows into a trailing portion of the gutter. The mouth is configured to channel water runback rivulets into the trailing portion of the gutter. The gutter can be a first gutter of a plurality of side by side gutters, each including a respective mouth narrowing into a respective trailing portion, wherein the gutters are separated from one another by respective rails.

An ice protection system includes an aircraft surface and a gutter defined in the aircraft surface between raised rails. The gutter includes a mouth that narrows into a trailing portion of the gutter. The mouth is configured to channel water runback rivulets into the trailing portion of the gutter. The gutter can be a first gutter of a plurality of side by side gutters, each including a respective mouth narrowing into a respective trailing portion, wherein the gutters are separated from one another by respective rails.

There is provided a system and a method for operating a multi-engine rotorcraft. When the rotorcraft is cruising in an asymmetric operating regime (AOR) at least one engine is an active engine and is operated in an active mode to provide motive power to the rotorcraft and at least one second engine is a standby engine and is operated in a standby mode to provide substantially no motive power to the rotorcraft, at least one of a power level of the at least one second engine is increased and at least one variable geometry mechanism of the at least one second engine is moved to shed any ice accumulation on the at least one second engine.

There is provided a system and a method for operating a multi-engine rotorcraft. When the rotorcraft is cruising in an asymmetric operating regime (AOR) at least one engine is an active engine and is operated in an active mode to provide motive power to the rotorcraft and at least one second engine is a standby engine and is operated in a standby mode to provide substantially no motive power to the rotorcraft, at least one of a power level of the at least one second engine is increased and at least one variable geometry mechanism of the at least one second engine is moved to shed any ice accumulation on the at least one second engine.

An ice protection system adapted to protect at least one ice-susceptible flight surface of an aircraft includes a mechanical ice protection device attached to the flight surface. A controller controls a power source that causes the mechanical ice protection device to change in shape and, thereby, change an aerodynamic characteristic of the flight surface. This change in shape happens only when the current thickness of ice on the surface exceeds a minimum thickness.

A de-icing assembly for a surface of an aircraft includes: a carcass with a first layer, a second layer, and a carcass centerline and a plurality of seams sewn into the carcass, wherein the plurality of seams join the first and second layers of the carcass together. The assembly includes a plurality of inflation passages formed by the plurality of seams and disposed between the first and second layers of the carcass. The system also includes a manifold fluidly connected to and disposed beneath the carcass, the manifold comprising a width and a manifold centerline oriented approximately perpendicular or parallel to the carcass centerline. The seams are sown by a stitchline formed of carbon nanotube yarn

Active surface structures comprise an exposed surface, a controlled group of MEMS (micro-electro-mechanical system) actuators, and a controlled region of the exposed surface corresponding to the controlled group. The controlled region has a first state, and a second state that is less textured than the first state. Active surface structures may be part of an apparatus that includes a controller and/or one or more sensors. The controller, sensors, and the controlled region may form a feedback loop in which the active surface structure is actively controlled.

Active surface structures comprise an exposed surface, a controlled group of MEMS (micro-electro-mechanical system) actuators, and a controlled region of the exposed surface corresponding to the controlled group. The controlled region has a first state, and a second state that is less textured than the first state. Active surface structures may be part of an apparatus that includes a controller and/or one or more sensors. The controller, sensors, and the controlled region may form a feedback loop in which the active surface structure is actively controlled.