Gravelkit is a term for a modification which is used on some airplanes to avoid foreign object damage (FOD), while operating on unpaved surfaces. Modification generally includes a method of preventing the nose gear spraying FOD into the engine, and a method of preventing the engine from sucking up FOD from the ground directly in front of it.
An example of planes that can be fitted with this upgrade is the Boeing 737-200, which includes a gravel deflector (similar in appearance to a ski) mounted to the nose wheel, and vortex dissipators using compressor bleed air on each engine. This modification was used by Alaska Airlines for many years, and is still employed by Canadian North, Air North, Nolinor Aviation, and First Air in northern Canada.
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|A Canadian North Boeing 737 fitted with a gravelkit|
|A First Air Boeing 737 fitted with a gravelkit|
|An Alaska Air Boeing 737 fitted with a gravelkit|