Free Flight Model Airplane Plans on the internet.
The internet is an amazing resource for the model builder. There are several web sites offering model airplane plans at no cost. The following list is for those plan sites that offer free plans. Below that are links to plan that are for sale.
Free Plan Sites
The Plan Page: http://www.theplanpage.com/prev.htm
Without a doubt the best source for Old Time Free Fight plans is the Plan Page. There are scans from original magazine articles. The plans can be printed full scale. I have made several models from this resource including the Smoothie, the Ying and the Sportster.
The House of Frog, i.e., Fly Rise Off Ground. http://www.houseoffrog.co.uk/ This site is from the UK and features trainer and some duration free flight models.
Italian Free Flight Plans: http://www.riviste-di-aeromodellismo.it/index_eng_bis.html This is a huge resource of free flight plans from the 20's on up. Many are jpg so enlarging requires some creative interpreting to get a usable plan.
Paul Bradley Model Airplane Page: http://parmodels.com/Plans/nocals.htm Here again is an individual just putting up plans for anyone to grab. Mostly scale designs here.