The purpose of these devices is to prevent ingestion of water or slush into engines, or to limit ingestion to nonhazardous quantities. A further purpose may be to prevent impacting of the deflected spray into pusher propellers or upon other parts of the aircraft in a harmful manner. These devices may be a part of the tires, or installed on the landing gear or upon other parts of the aircraft. Considerations should cover all applicable ground operating modes including use of reverse thrust, and be extended to cover possible damage to mechanisms, systems, antennae or pitot and static ports.
Ingestion of tire deflected water or slush has caused powerplants to lose power when no precautions were taken. Certification requires establishment of safe and acceptable air vehicle operation.
Past aircraft operation has shown that there is a need to substantiate the capability of aircraft to operate safely from runways having standing water or slush over all or parts of the surface.