Book Chapter 10 Page 1

Chapter 10: Helicopters, Commercial & Regional Aircraft

Circa 1500 A.D., Leonardo da Vinci made drawings of and performed experiments with models of an aircraft with a helical rotor. His drawing called for the use of muscle power which would not have been powerful enough to operate the machine.

Many other experimenters during the 20^th century tried to solve the problem of vertical lift. A Spanish inventor, Juan de la Cierva, developed a hinged, flapping rotor blade that made the development of practical helicopters possible. The rotor of a modern helicopter has 2, 3 or 4 blades radiating from a central hub. Army helicopters such as UH-1 Huey (pictured below) and UH-60 Sikorsky Blackhawk (utility aircraft) and AH-1W Sea Cobra and AH-64 Apache (attack aircraft) all have critical components manufactured by SIFCO.

In Vietnam helicopters came into their own as a combat weapon. They were used to evacuate wounded, transport personnel and cargo and observe enemy activities.

Introduction