Helicopters

David Clay Richard Cody

Brief history of helicopters

• Helicopters were the first heavier then air design by Da Vinci• In 1906 gyroplane no.1 was created• In 1924 Etienne became the first to fly a kilometer in a closed circuit

with a helicopter• In 1952 the world's first transatlantic helicopter crossing was

completed• In 1957 the world's first remotely piloted vehicle was created• In 1982 the first transatlantic helicopter crossing was completed,

5100 miles• 1992 Venezuela to Spain, the flight was the longest over ocean

flight.

Okay, now that you know a little bit about helicopter history let us move on to helicopter concepts.

Table of Words

• Advancing blade• Retreating blade• Blade stall• NOTAR• Tilt rotor• Torque• Collective• Cyclic

• Skids • Translation• Swash plate• Yaw• Hover• Tail rotor• Main Rotor• Tandem rotor

Blade

Retreating blade• The blade that moves the

opposite direction as the aircraft.

Advancing blade

• The blade that is moving the same direction as the aircraft.

Blade

Retreating blade Advancing blade

Blade stall

• When a blade is no longer providing lift.

• The rotor blades traveling away from the direction of flight enter a stalled condition.

• Solved by adding flex in the blade

NOTAR

• Is an acronym for No Tail Rotor

• Anti-torque system

Tilt rotor

• A tilt rotor helicopter combines the vertical lift capability of a helicopter with the speed and range of a turboprop airplane.

Torque

• Torque is a rotation or a twist

Collective

• Controls the pitch angle of all the main rotor blades

Cyclic

• Controls the helicopter’s movement forward, backwards, and sideways.

Skids

• The things on witch a helicopter rests

Translation

• The movement of the helicopter. On the horizontal plane

Yaw

• Yaw is the helicopters ability to rotate about a vertical axis

Hover

• A helicopter is hovering if it is in nearly stationary flight

Tail Rotor

• The tail rotor is used like a small propeller, to pull against torque reaction and hold the helicopter straight.

• If you spin a rotor using an engine, the rotor will rotate, but the engine and the helicopter will try to rotate in the opposite direction

Main Rotor

• A helicopter's main rotor is the most important part of the vehicle. It provides the lift that allows the helicopter to fly, as well as the control that allows the helicopter to move laterally, make turns and change altitude.

Tandem Rotor

• In a tandem rotor helicopter, you have no tail rotor. Another main rotor rotating in the opposite direction of the front rotor takes the place of the tail rotor. By spinning in the opposite direction it negates the torque of the front rotor with torque of its own.

Sources

• http://images.google.com

• http://www.aviation-terms.com

• http://science.howstuffworks.com/helicopter5.htm

• http://dictionary.reference.com/

• http://aerospaceplanes.suite101.com/

• http://www.helis.com/howflies/prflight.php