Aircraft tyres on a commercial jet are an amazing example of advanced design and manufacture. After all they have to hit the tarmac and after an initial skid accelerate to 170 miles per hour and safely support the weight of a small office building.
But after six months, or 300 landings, they need replacement.
Although some can find further use on farm equipment or backhoes, most are ground into crumbed rubber for use in playgrounds and sporting fields.
Unfortunately, there is a limit on how much can be used for these purposes. Inevitably a large percentage is burnt as furnace fuel.