Patents generally give cover for 18 years, then are extendable for 2-3 years more at exceptional cost. Once the patent has expired royalties usually are no longer paid. Copyright, Registered Design and Registered Trade Mark owners fare MUCH better and for hugely less cost, the greatest iniquities in Intellectual Property law; inventors are cash cows and disposable.
I have been pondering about craft which glide and fly without mechanical 3 axis control (not including lighter-than-air-craft) :
Various gliders from Otto Lillienthal's up to modern hang gliders etc. are controllable by shifting body weight.
Various micro-lights and para-gliders also do not appear to have controls for all 3 axes.
Autogyros, including the unpowered Focke-Achgelis Fa 330 "Bachsteze" do not have 3 axis control.
The Harrier and other vectored Thrust planes have 3 axis controls, but are not solely reliant on these and can perform amazing manoeuvers with reduced or even no use of the normal 3 axis control systems.
This seems to highlight that talk of "The First To Fly" inevitably requires EXACT definition of all the various parameters and these parameters then exclude various machines which SHOULD be included. Could Pearse's plane have been controlled by body movement?
Now, over 100 years since any of "the first" alleged powered, controlled sustained flights, can we ever know CATEGORICALLY whether gradients, head wind, human or mechanical assistance, exaggeration, unreliable witnesses, vested interests, Lawyers, National pride or other factors might have tipped the scales?