to prevent ingestion of FOD during take-off from rough airfields. The main air intakes could be closed with mesh doors and special inlets on the top of the intakes temporarily opened. This would allow enough airflow to the engine for take-off but reduced the chances of the engine sucking up objects from the ground. Another interesting design to minimize the risk of FOD is the Antonov An-74 which has a very high placement of the engines. Boeing offered a gravel runway kit for early 737s that allows the plane to be used from unimproved and gravel runways, in spite of having very low-slung engines. This kit included gravel deflectors on the landing gear; foldaway lights on the bottom of the plane; and screens that prevented gravel, which would enter the open wheelwells when the gear was extended, from hitting critical components. The kit also included vortex dissipators, devices which would reduce the airflow into the engine from the bottom so as to reduce the likelihood of ingesting gravel. Airbus engineers are investigating a novel approach to reducing FOD. By developing, in conjunction with Israel Aerospace Industries, the Taxibot, a tractor controlled by the pilot, aircraft will not need to use jet engines while taxiing, and therefore they will not be vulnerable to FOD on aprons or taxiways. FOD damage examples Vehicle tire track-in Debris is often trapped in the treads of tires from vehicles coming onto an airfield. Types of debris trapped in a vehicle tire can include rocks, mud, stones, loose hardware (screws, washers, bolts, ect.) and many other forms of small materials. These can be crew & fuel trucks, maintenance vehicles and many others that inadvertently bring and deposit debris around a flight line. These types of FOD are very difficult to track and manage once they are introduced into the airfield. The debris can then easily be picked up by jet engine intake, engine blast and prop/rotor draft. This material, once loose around operational aircraft, can lead to serious safety concerns including personnel injury and equipment/property damage. Runway debris The crash of a Concorde, Air France Flight 4590, at Charles de Gaulle Airport near Paris on 25 July 2000 was caused by FOD; in this case a piece of titanium debris on the runway which had been part of a thrust reverser that had fallen from a Continental Airlines McDonnell Douglas DC-10 during takeoff about four minutes