History
What metal was too heavy for helicopters, and weren't exchanged until 1890?
Cast Iron
What is the defining characteristic of helicopters?
Their constant and consistent speed
What happens when the angle of attack is increased?
Rotor speed decreases
Who uses helicopters?
Most helicopters are used in the military or commercially.
Around what year did Gasoline powered engines become commercially available?
1920's
What is the unit of measure used when identifying how fast the blades are spinning?
Revolutions per minute (RPM)
What else increases when the wing’s angle of attack is increased?
Drag increases when the wing’s angle of attack is increased.
Name two CF helicopters
CH-149 CORMORANT, CH-148 CYCLONE, CH-146 GRIFFON, CH-139 JET RANGER, CH-124 SEA KING.
What metal was finally starting to be used during 1890s but weren't yet widely available?
Aluminum
What happens if the rotor goes too fast?
Lift will be lost and damage to blades will occur.
How is lift increased with a rotary wing?
Increasing the wing’s angle of attack increases lift with a rotary wing.
Most military helicopters do not have which kind of engine?
Piston-powered engine.
When were the first internally combustable powered engines available?
20th Century
Why can't Rotor Under Load Can Be Allowed to Go Too Slow?
Because the blades rely on centrifugal force to stay horizontally extended.
How does a helicopter engine prevent the rotor from slowing when drag increases?
A proportionate change in power is required to compensate for the increase in drag.
Commercially used helicopters have what type or ratio?
Power-to-Weight.
When was aluminum widely available and used in aeronautical machines?
1920
Is it possible for tips to exceed the speed of sound?
Yes, it produces increased drag and vibration.
To decrease the lift of a fixed-wing aircraft, the wing’s angle of attack is?
Decreased.
How many turbines does a turboshaft engine have?
A turboshaft engine has two turbines: one for its own compressor and one for the main rotor.