5. Flying boat
This crazy plane, the Dornier Do X, was the largest, heaviest flying boat when it was first produced in 1929. It was built by German engineers and was enormously popular with the public. Unfortunately, they couldn’t quite find a commercial use for it. A lack of commercial interest and a number of accidents (none of them fatal, luckily), no more than three of these were ever built.
Continue on to the next page to take a look at the next crazy airplane!