Some plane crashes do have a happy ending. German photographer Dietmar Eckell spent three years, traveling to four continents to find 15 aircraft crash sites where everyone on board survived. His quest took him to deserts, swamps, jungles and mountain tops. He features his photographs in a book called Happy End. He paid for the travel and the book through crowdfunding. Dietmar Eckell talks about these aviation miracles and why many of the planes are remarkably well preserved.