Helicopters

 

Although the first helicopter was invented in 1907 the first one to be mass produced was engineered in 1939 after the invention of the fixed wing airplane. Some common uses for helicopters include the transport of military passengers, to conduct search & rescue missions, for emergency transportation as well as for sight seeing tours. There are some of us who have even heard and observed helicopters over our heads in various neighborhoods and locations. My personal experience with helicopters have been relatively positive; while visiting Myrtle Beach one summer is where I took my first helicopter ride. I still remember the pilots initial advice, "watch your head, those blades are sharp!"

Similar to an airplane a helicopter requires lift and thrust forces for it to fly, however the helicopter uses a different wing system. The blades of a helicopter are known as the main rotor or rotor system with the main blade being located on the top of the body of the helicopter. The main blade rotates in a circular motion to lift the helicopter off the ground. For a helicopter to hover it is dependent on the lift and thrust forces being equal to the weight and drag forces. When lift and thrust forces are greater than weight and drag forces the helicopter ascends upward. Whereas when lift and thrust forces are less than weight and drag forces the helicopter descends downward. For the helicopter to fly forward, sideward or rearward the helicopter must be tilted in the direction in which you desire to fly.