1. AVIATION HISTORY WEEK 10 Helicopters

2.  Introduction  How a helicopter flies  The advantages of Helicopter

3. Introduction  Helicopter is an aircraft than can take- off and land vertically.  They have existed for 70 years & become one of the most versatile and vital vehicles in the world. Early helicopters First flown in 1936

4. Basic Helicopter Rotor: The rotating part of any device

5. Basic Helicopter  Main Rotor  Long, flat blades that spin & give a helicopter lift & thrust.  It determine the helicopter direction.  Drive Shaft  Long cylindrical rotating rod for the transmission of power.  Tail Rotor  A small rotor at the back.  It blow air sideways to give balance.  Without tail rotor, the torque would force the helicopter body to rotate in the opposite direction.  It also used to turn the helicopter

6. Basic Helicopter  Engines  Used to power the helicopter.  Cockpit  The area where the pilot sits and control the helicopter.  Cabin  The area where passengers or other things are carried.  Landing Skids  Long metal feet for helicopters stand on when they are on the ground.

7. How does Helicopter Flies?

8. How helicopter flies?  The helicopter engines will provide the energy/power to turn the main rotor blades.  As the rotor blades turn it will create Lift and Thrust force.  The rotor blades have an airfoil shape, so as the rotors turn, air flows more quickly over the tops of the blades than the below.  Thus, 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 and gives the helicopter the lift it needs to fly.  However, when the rotor blades turns, it also produces reaction torque which tends to make the helicopter’s body spin also.  So, the tail rotor at the back is used to prevent the helicopter’s body to spin.  On twin-rotor blades the rotors turn in opposite directions, so their reactions cancel each other.  The helicopters can change their direction by changing pitch angle of the helicopter’s rotor blades.

9. Basic Helicopter

10. The Uses of Helicopter ConstructionCommercial Firefighting Search & Rescue Military Bell 205 dropping water on fire Sikorsky S-64 Skycrane lifting a mock-up house WAH-64 ApacheWAH-64 Apache attack helicopter

11. The Uses of Helicopter Commercial Helicopters  Mainly used for transport. Construction Helicopters  Helicopter that are used in construction to carry loads are called skycranes.  The heavy loads carried by skycranes are connected to long cables.  Are also used to place heavy equipment on the tops of tall buildings.

12. The Uses of Helicopter Search and Rescue Helicopters  Used for emergency medical assistance when an ambulance cannot easily or quickly reach the scene. Firefighting Helicopters  Used to combat fires.  These helicopters are often called Helitacks.  Helitacks carry water to perform water bombing onto the fire.

13. The Uses of Helicopter Military Helicopters  Are used mainly for attack and for transport.  Attack helicopters are equipped with missile or miniguns which are used to attack ground targets.  Transport helicopters are used to carry troops and supplies when transport via typical military cargo is not possible.

14. What are the advantages of the helicopter compare to airplane

16. Bell UH-1 Iroquois (Huey)- The most famous helicopter in the world with several unique characteristics Serve as medical evacuation, instrument trainer andmedical evacuation general utility aircraft

17. Advantages of Helicopter  Can hover (can remain in one place in the air)  Can fly backwards (reverse)  Can rotate in the air (360 degrees)  The capability to efficiently hover for extended periods of time, reverse and rotate allows a helicopter to accomplish tasks that airplane cannot perform.

18. Advantages of Helicopter

19.  Versatile (able to perform many functions)  Helicopter functions include transportation, construction, fight fires, search and rescue, military uses and also can rescue people trapped in burning buildings.  Flexible  As helicopter do not need runway for take-off and landing, it can fly almost anywhere.  Can deliver huge loads to areas that no other vehicle can reach. For example congested or isolated areas and deep jungle.