On this day in 1976, as our faithful chronicler reminds, during a photoshoot for the cover art for their tenth studio album, a concept one called Animals (with deference to George Orwell), Algie the pig balloon, moored the previous day near Battersea Power Station, the iconic facility to be condemned imminently having reached the end of its useful life, broke free during wind gusts.
Pink Floyd had commissioned the former Zeppelin manufacturer Ballon Fabrik to make the twelve metre pig balloon—to be inflated with helium—with an expert marksman on site to shoot it down in case it drifted out of control. The designated sniper was not present for this daring escape and the dirigible floated over Heathrow, forcing the airspace to close. The pig was recovered at a farm in Kent three days later as filming continued, but it was decided that the preliminary shots of the power station had turned out better and to superimpose Algie flying between the chimney stacks. The stunt has been successfully staged several times afterwards, including for the 2012 London summer Olympics.