Deicing boot

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A deicing boot is a device installed on aircraft surfaces to permit a mechanical deicing in flight. Such boots are generally installed on the leading edges of wings and control surfaces (e.g. horizontal and vertical stabilizer) as these areas are most likely to accumulate ice and any contamination could severely affect the aircraft's performance. A deicing boot consists of a thick rubber membrane that is installed over the surface. As atmospheric icing occurs and ice builds up, a pneumatic system inflates the boot with compressed air. This expansion in size cracks any ice that has accumulated, and this ice is then blown away by the airflow. The boots are then deflated to return the wing or surface to its optimal shape.

Deicing boots, were invented by the B.F. Goodrich corporation (now just Goodrich) in 1923 in Akron, Ohio.

Because they are an older technology, they have some drawbacks. Boots need to be replaced frequently (on the order of 2-3 years) and proper care for deicing boots is critical. Any holes in the boot will create air leaks that will decrease, if not eliminate, any effect that the boots may have. As such, boots must be carefully inspected before each flight and any holes or cuts must be patched.

While deicing boots have undoubtedly saved many lives and have permitted flight into known icing conditions, it is important to note that they are unable to handle extremely severe icing. In these cases, ice can accumulate faster than the boots can shed it or, ice can accumulate on non-booted surfaces to the point where it weighs the aircraft down until it is overweight and no longer flyable.

Deicing boots are most commonly seen on medium-sized airliners and utility aircraft. Larger airliners and military jets tend to use heating systems that are installed underneath the wing's leading edge, keeping it constantly warm and preventing ice from forming.

Other applications for larger commercial aircraft usually include, but are not limited to, electrothermal systems, and Bleed Air systems. Electrothermal usually require substantial electrical power and is generally limited to large aircraft which can supply this energy through generators. Bleed Air systems use hot air from the engine manifolds which is routed via high pressure ducting (piccolo ducts) to the leading edge (main) of the wings, and/or horizontal and vertical tail stabilizers.

With Boeing's use of electrothermal ice protection on the wings of the 787 and with Boeing's More Electric Aircraft (or even All Electric Aircraft) initiative, electrothermal ice protection systems are being considered more prominently than boots and bleed air systems on commercial aircraft. General aviation jets also are studying the effect on thrust and fuel consumption of bleed air and additional benefits of its removal. See paper AIAA 2006-228 by John Ensign and Dr. John Gallman from the Cessna Aircraft Company.