A gravel kit is a modification on an aircraft to avoid foreign object debris (FOD) damage or ingestion while operating on unpaved surfaces. Modifications generally include methods of preventing the nose gear spraying FOD into the engine and onto the underside of the fuselage or wings, and methods of preventing each engine from ingesting FOD from the ground directly in front of it. * Canadian North 737-200 engine gravel kit vortex dissipator * Canadian North 737-200 engine gravel kit vortex dissipator in profile view * Gravel kit on a landing Air North 737-200 * Gravel kit on a First Air 737-200