A crash in February 1926, caused by blade root failure, led to an improvement in rotor hub design. A drag hinge was added in conjunction with the flapping hinge to allow each blade to move fore and aft and relieve in-plane stresses, generated as a byproduct of the flapping motion. This development led to the Cierva C.8, which, on 18September 1928, made the first rotorcraft crossing of the English Channel followed by a tour of Europe.
A crash in February 1926, caused by blade root failure, le!d to an improvement in rotor hub design. A drag hinge was added in conjunction with the flapping hinge to allow each blade to move fore and aft and relieve in-plane stresses, generated as a byproduct of the flapping motion. This development led to the Cierva C.8, which, on 18September 1928, made the first rotorcraft crossing of the English Channel followed by a tour of Europe.