Although there have been various designs resembling helicopters centuries before, and flying rotorcraft designs built and flown in the early 20th century, the first successful, practical and fully controllable helicopter was flown in 1936, the German Focke-Wulf Fw 61. In 1942, the Sikorsky R-4 was the first to reach full-scale production. One of the big advantages of a helicopter is the ability to take-off and land vertically, ideal for short runways and hard to reach areas, as well as being able to hover on the spot. They took longer to adapt than aircraft due to higher engine power density requirements. Improvements in fuel and engine technology during the second half of the 20th century led to big advancements as a result; one of these was the introduction of the turbine engine in the 1950s.gy, although too late to make an impact in the war. Since then, technology has continued to rapidly improve and aircraft remain an integral part of armies all over the world.