Helicopters turn thanks to their tail rotor blades and the swash plate assembly of their main rotor blades.
Pilots will control the helicopter’s tail rotor blades to turn the aircraft while it’s hovering. And they’ll turn it using the swashplate assembly of the helicopter’s main rotors while it’s in a forward movement.
Helicopters are able to hover in place thanks to their main rotor blades, which generate lift by pushing air downwards, and helicopters are able to remain hovering as long as the lift they generate equals their weight.
Helicopters can technically hover upside down, too, since all they need to do is to keep rotating their main rotor blades.
In practice, it’s extremely difficult to maintain an upside-down position during flight, though.
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How Helicopters Turn
A helicopter pilot turns by either using pedals to control the tail rotor or by tilting the main rotor.
Pilots will control the tail rotor to turn a helicopter while hovering in place.
They’ll control the main rotor’s direction to turn while in forward flight.
Hence, there are two types of helicopter turns:
1. Yaw: Turning while hovering
This type of turn is achieved using the tail rotor.
It’s analogous to being spun round and round in an office chair.
2. Roll: Turning while in flight
The type of turn is achieved by changing the direction of the chopper’s main rotor.
It’s analogous to leaning on one side of a bike during a fast turn.
How Helicopters Turn Left
To turn left, the pilot will push the left foot pedal while the helicopter is turning.
The tail rotor’s pitch will increase on all blades due to a mechanical or hydraulic link.
The increasing blade pitch results in greater thrust than fuselage torque, which will push the helicopter’s tail rightward.
The chopper will rotate to the left as a result.
How Helicopters Turn Right
To turn right, the pilot pushes on the right foot pedal while the helicopter is hovering.
The tail rotor’s pitch will decrease on all blades.
The resulting thrust is less than the fuselage torque, and the torque pulls the helicopter’s tail leftward.
As a result, the helicopter rotates to the right.
How Helicopters Rotate
Helicopters rotate due to pitch changes in the tail rotor blades.
The pilot changes the helicopter’s tail rotor pitch using the pedals in the cockpit.
The pedals provide the pilot with directional control, letting them rotate the helicopter around its vertical axis.
This system works with a series of shafts connecting the drive shaft with the tail boom.
A gearbox at the tail boom’s end gives the tail’s rotor an angled drive.
How Helicopters Fly Forward
A pilot flies a helicopter forward by tilting its swash plate assembly with the cyclic, altering each blade’s pitch while it rotates.
The result is that every blade produces maximum lift at a specific point.
The lift is highest at the back of the helicopter, and the chopper’s angle of attack is increased.
The consequence of this phenomenon is that the rotor generates both lift and thrust in the direction the swash plate assembly tilts.
How Helicopters Fly Backward
The pilot changes the angle of attack by tilting the swash plate assembly backward.
Doing so causes a difference in pitch between the chopper’s main rotor blades.
The rotor blades at the front of the helicopter will generate the highest lift, while those at the back produce the smallest.
The result is that the helicopter will fly backwards in the direction that the swash plate assembly was tilted.
How Helicopters Fly Upside Down
Helicopters fly because their rotors generate lift.
So as long as helicopter rotors are spinning, they should be able to fly even when upside down.
Even though an upside-down helicopter flight makes theoretical sense, it isn’t practical.
Modern helicopters are not designed to fly upside down.
And most modern helicopters cannot maintain more than a few minutes of upside-down flight.
How Helicopters Hover
Helicopters hover by creating lift through their main rotor blades.
The rotor blades deflect air downwards, which creates the lift that keeps the helicopter off the ground.
The helicopter will hover as long as the lift it produces equals its weight.
In conclusion:
- Helicopters use their tail rotors to turn while hovering and the swash plate assembly on their main rotor to turn while flying forward.
- The pilot controls the helicopter’s tail rotors with a set of left and right pedals in the cockpit.
- The pedals adjust the pitch of the tail rotor’s blades, causing the aircraft to rotate on its vertical axis.
- To fly forward, the pilot will tilt the main rotor’s swash plate assembly in the desired direction.
- Doing so alters the helicopter’s angle of attack such that it flies in the desired direction.
- Helicopters can hover because their main rotors displace air downwards, which generates lift.
Helen Krasner holds a PPL(A), with 15 years experience flying fixed-wing aircraft; a PPL(H), with 13 years experience flying helicopters; and a CPL(H), Helicopter Instructor Rating, with 12 years working as a helicopter instructor.
Helen is an accomplished aviation writer with 12 years of experience, having authored several books and published numerous articles while also serving as the Editor of the BWPA (British Women Pilots Association) newsletter, with her excellent work having been recognized with her nomination of the “Aviation Journalist of the Year” award.
Helen has won the “Dawn to Dusk” International Flying Competition, along with the best all-female competitors, three times with her copilot.
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