It is a great privilege for me to give the Eighth Cierva Memorial Lecture and to pay tribute and honour to Juan de la Cierva who, more than any other inventor, was responsible for bringing into reality the principle of rotating wing flight. Cierva was an inventor of indefatigable industry, patience and genius. His faith in the Autogiro and the future of the rotating wing aircraft will be remembered for ever.

The invention by Cierva of the articulated rotor with flapping and drag hinges to relieve bending stresses at the blade root, and in the chord-wise plane, provided the solution to true helicopter flight which become a reality in 1936.