Helicopters

1. Helicopters By: Loren Kanov March 12, 2001 Honors Physics Mr. Pagani Period 6

2. Table of Contents • History of Helicopters • Significant Contributions • Igor I. Sikorsky • How it Works • How it Maneuvers • Resources

3. History of Helicopters • The ancient Chinese had toys that rose upward when spun rapidly. • Leonardo Da Vinci made drawings of what we now know as the helicopter. • The invention of the internal combustion engine made it possible to develop full-sized models with an adequate power source.

4. Significant contributions • 1907: French pioneer Paul Cornu lifted a twin-rotored helicopter into the air entirely without assistance from the ground for a few seconds. • 1924: French pioneer Etienne Oehmichen became the first to fly a helicopter one kilometer in a closed circuit. It took 7 minutes and 40 seconds. • 1936: Spaniard Juan de la Cierva created the autogyro which was not a true helicopter, but reached new heights in vertical flight.

5. Igor I. Sikorsky • Designed the world’s first true production helicopter • Greatly influenced in contemporary science by his mother and father • As a child, he built model aircraft and helicopters • Achieved international recognition in 1913 for designing and flying the first multimotor airplane • In late 1938, United Aircraft management approved his experimental helicopter and on Sept. 14, 1939, the VS-300 made its first flight • His single-rotor design remains the dominant configuration of helicopters today

6. How it works

7. Direction: The helicopter has two jet turboshaft engines which turn the rotor blades As the blades sweep through the air, they form what is called the “rotor disc” The rotorhead, which is where the blades are connected, is controlled by a swash plate which transfers the pilot’s instructions to the rotor blades By raising and lowering each blade at a precise point in its revolution, the pilot tilts the rotor disc in the desired direction Control: A cyclic control stick tilts the rotor disc in the desired direction and controls speed The collective pitch lever connects to the swash plate and changes the pitch of the rotor blades in unison, enabling the helicopter to climb or descend Foot pedals connected to the control arms on the tail rotor blades work together with the cyclic control stick to make right or left turns How it works

8. Lift: The rotor blades are shaped like the wings of an airplane: curved on top and flat on bottom When they rotate, the pressure of the slower-moving air flowing under the blade is greater than the faster-moving air above it This difference in pressure pushes the blades up, giving the helicopter the lift it needs to fly Balance: Without a tail rotor, the body of the helicopter would be forced in the opposite direction of the spinning rotor blades The tail rotor compensates for this by providing lateral thrust in the opposite direction, holding the body stationary How it works

9. How it maneuvers • Changing the angle or tilt of the helicopter’s rotor blades tells the aircraft whether to move forward or backward or to hover motionless in the air. Forward Hover Backward

10. resources