I realise there isn't really a source for this and is just a forum post, but still found it interesting none the less...
In the '50s, North American scholars became aware of a series of 1.000 years old Inca aircraft-like gold artifacts, sent by Colombian government to further analysis in the USA. The conclusion of mainstream archeologists was that the artifacts were nothing but "stylized ceremonial birds".
In the '70s, maybe compelled by Erich Von D