Start…
Helicopters
Past,
Present, and Future
By Billy Petersen TEL 353 Fall 02
Helicopters
History
Rotors
of Vertical Flight Functions of Helicopters Wheels or skids Helicopter Achievements
Principles
History
Chinese Da Vinchi’s Great Vision He`licopte`re Invention of the IC engine
Ancient
Rotors
Main Tail
Rotor
Rotor
NOTAR
Cont…
Main Rotor
on the top of the craft The main rotor produces the lifting force Lift allows the helicopter to rise vertically or hover Tilting the main rotor causes flight in the direction of the tilt
Located
Main Rotor
Rotor Hub
Blade
Advanced Tip Shape For Low Noise
Tail Rotor
at the tail of the aircraft Vertical flight is impossible without it What will happen if the tail rotor fails in mid-flight?
Located
Tail Rotor
Tail Rotor
NOTAR
NOTAR NOTAR
stands for No Tail Rotor
uses jet thrust instead of tail rotor blades for direction, stability and it also lowers noise helicopters are the quietest in the world Cont…
NOTAR
NOTAR
Principles of Vertical Flight
Rotation
Torque
Torque IGE OGE
Cont…
compensation
Principles of Vertical Flight
Cont…
Recirculation
of lift Collective pitch Cyclic pitch
Dissymmetry
Rotation, Torque, Torque Compensation
Torque
Torque Compensation
Rotation
IGE and OGE
stands for In Ground Effect IGE is the force that provides less engine power to enable the helicopter to initially lift off the ground due to downwash from the main rotor OGE stands for Out of Ground Effect
Cont…
IGE
IGE and OGE
OGE
Cont…
is the complete opposite of IGE OGE is when there are no hard surfaces underneath, and more engine power is needed to keep the helicopter at a constant altitude
Recirculation and Dissymmetry of Lift
Recirculation
occurs at a low hover during IGE and requires more power to hold a constant height Dissymmetry of lift occurs in forward flight
Collective Pitch and Cyclic Pitch
Collective pitch is the changing of all the rotor blades’ pitches simultaneously To climb, the angle is increased To descend the angle is increased Cyclic pitch is used during forwards, backwards, or sideways flight
Cont…
Collective Pitch and Cyclic Pitch
Cont…
The cyclic pitch is changed by changing the angle of the entire rotor, not just the angle of the blades in collective pitch
Functions of Helicopters
Transportation Medivac Search and Rescue Construction Fire fighting
Mail Service Observation Arial photography Traffic control
Cont…
Functions of Helicopters
Farming
and
fertilizer spreading Cattle control
Nile control Military And many more
West
Wheels and Skids
are very heavy and used for larger crafts Wheels enable the helicopter easy mobility while on the ground
Wheels
Wheels and Skids
are lightweight and used for smaller crafts Skids require the helicopter to be jacked up and rolled, or to be placed on a flatbed for moving
Skids
Helicopter Achievements
1951 – The Kaman K-225 became the world’s first turbine gas helicopter 1952 – First transatlantic crossing with stops 1957 – Dwight Eisenhower became the first president to fly in a helicopter 1961 – The Mil Mi-6 became the first helicopter to exceed 300 km/hr Cont…
Helicopter Achievements
– The Lockheed XH-51 reaches 487 km/hr 1967 – First non-stop transatlantic flight September 1, 1982 – Ross Perot Jr. and Jay Corburn are the first to fly around the world. They made the trip in less than 30 days
1967
The End