I'm only asking because usually VIP/Executive heavy jets put covers on the engines during nightstops (obvious reasons: prevent FOD being blown into the engines, prevent unnecessary 'windmilling' or the blades and even just to prevent the highly polished intakes from tarnishing...) but I've never ever seen covers on Amiri 747s, 777s, BBJs... Was just wondering why? I mean, If you have such immensely valuable aircraft, why not follow the 'usual/ practice of looking after them?