I dimly recall an exceptionally heavy snow fall at Stansted in the late 60's I think. Out came the snow clearance vehicles that hadn't been used for years. It wasn't until the entire length of 23 had been swept down the centre-line that someone noticed that most of the wire bristles from one of the machine's brushes had fallen out. Where were they? Scattered down the entire length of what had been swept! FOD with a vengeance. Use 'em or lose 'em I suppose. Mind you, Stansted then wasn't what you would call "busy".