In 1960, investigators found dark bits of feather stuck inside a crashed airplane's engines. They needed someone to figure out what bird they belonged to—and how that bird took down a 110,000-pound plane. Enter Roxie Laybourne, a Smithsonian bird expert who not only answered that question, but also invented the science of using feathers to solve bird-related mysteries. This time on Sidedoor, we revisit some of Roxie's greatest cases and learn how she and her team helped keep the friendly skies friendly for both birds and people.