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.

A method of making an adhesive for an ice protection assembly includes mixing ferrous nanoparticles into the adhesive. Removal of the adhesive for ice protection assembly inspection or repair includes heating the ferrous nanoparticles in the adhesive to soften the adhesive and allow for easy removal or repositioning of the ice protection assembly.

A method of making an adhesive for an ice protection assembly includes mixing ferrous nanoparticles into the adhesive. Removal of the adhesive for ice protection assembly inspection or repair includes heating the ferrous nanoparticles in the adhesive to soften the adhesive and allow for easy removal or repositioning of the ice protection assembly.

Anti-icing stacks for protecting an aerodynamic surface are described. In some embodiments, an anti-icing stack includes an anti-icing layer, an elastomeric erosion protection layer, and an additional layer. The erosion protection layer is disposed between the anti-icing layer and the additional layer. The additional layer has a thickness greater than the thickness of the erosion protection layer and a tensile modulus of no more than the tensile modulus of the erosion protection layer. The additional layer may be a foam adhesive layer.

Anti-icing stacks for protecting an aerodynamic surface are described. In some embodiments, an anti-icing stack includes an anti-icing layer, an elastomeric erosion protection layer, and an additional layer. The erosion protection layer is disposed between the anti-icing layer and the additional layer. The additional layer has a thickness greater than the thickness of the erosion protection layer and a tensile modulus of no more than the tensile modulus of the erosion protection layer. The additional layer may be a foam adhesive layer.

A heating element and conductive element system may include a heater conductive element and a heating element. The heater conductive element and the heating element may be integral components. The heater conductive element and the heating element may be discrete components. The heater conductive element may be configured for enhanced mechanical fatigue compared to typical conductive element.

An assembly is provided for a structure. This assembly includes a composite skin and a thermal anti-icing system. The composite skin extends between an exterior surface and an interior surface. The thermal anti-icing system includes a susceptor and a waveguide. The susceptor and the waveguide are integrated into the composite skin between the exterior surface and the interior surface. The waveguide is configured to direct microwaves to the susceptor for melting and/or preventing ice accumulation on the exterior surface.

An assembly is provided for an aircraft structure. This aircraft structure assembly includes an acoustic panel and a thermal anti-icing system. The acoustic panel includes an exterior surface. The thermal anti-icing system includes a susceptor and a microwave system. The susceptor is configured with the acoustic panel. The microwave system is configured to direct microwaves to the susceptor for melting and/or preventing ice accumulation on the exterior surface.

A method of making an adhesive for an ice protection assembly includes transferring Z-CNTs from a substrate carrier into the adhesive. De-bonding of the adhesive for ice protection assembly inspection or repair or repositioning at initial installation includes heating the Z-CNTs in the adhesive to soften the adhesive and allow for easy removal.

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.