Etymonline disagrees; -plane here is from French planer "to soar," ultimately from Latin planus, "flat." http://www.etymonline.com/index.php?term=aeroplane ht

Etymonline disagrees; -plane here is from French planer "to soar," ultimately from Latin planus, "flat." http://www.etymonline.com/index.php?term=aeroplane http://www.etymonline.com/index.php?term=aeroplane