Eufaula, Alabama. Eufaula is the largest city in Barbour County, Alabama, United States.
Leonardo da Vinci (1452â1519) is generally credited with inventing the helicopter, but the first practical design was developed only in the 1930s by Russian-born Igor Sikorsky (1889â1972). Today, typical uses for helicopters include military transportation and air-sea rescue.eonardo da Vinci (1452â1519) is generally credited with inventing the helicopter, but the first practical design was developed only in the 1930s by Russian-born Igor Sikorsky (1889â1972). Today, typical uses for helicopters include military transportation and air-sea rescue.
Theory of operation of the helicopter. Leonardoâs helicopter was designed as a human powered machine. Unfortunately for Leonardo, engines had not been invented yet and humans have nowhere near the power to weight ratio required for them to produce enough energy to lift themselves against the force of gravity.