Contents
- 1 What is helicopter feathering?
- 2 What is rotor blade feathering?
- 3 Which type of hinge is used for feathering?
- 4 What is coning effect in helicopter?
- 5 What are the strongest hinges?
- 6 What does flapping mean on a helicopter rotor?
- 7 Which is a side effect of increasing feathering?
- 8 Why do the blades move up and down on a helicopter?
What is helicopter feathering?
Feathering. The action that changes the pitch angle of the rotor blades by rotating them around their feathering (spanwise) axis. Feathering axis. The axis about which the pitch angle of a rotor blade is varied. Sometimes referred to as the spanwise axis.
What is rotor blade feathering?
Feathering the blade means changing the pitch angle of the blade. By changing the pitch angle of the blades you can control the thrust and direction of the main rotor disc.
What is collective feathering?
June 4, 2021 August 16, 2018 by ETL. Cyclic feathering is the term used to describe the changing of the blade angle separately for individual blades through pilot input via the cyclic. The pilot changes the angle of the stationary swashplate with movements of the cyclic.
Which type of hinge is used for feathering?
The third hinge in the fully articulated system is called the feathering hinge about the feathering axis. This hinge is responsible for the change in pitch of rotor blades excited via pilot input to the collective or cyclic.
What is coning effect in helicopter?
Coning is an upward sweeping angle of the rotor blades as a result of lift and centrifugal force. Conversely, the coning angle decreases when the centrifugal force increases as compared to the lift generated. When a helicopter transitions from the ground to a hover, the increase in coning angle is easy to see.
Do hinges open both ways?
Double-action, spring-loaded hinges allow doors to swing in both directions, as Hinge Outlet describes. You’ve probably seen them in restaurants or commercial buildings where traffic flows in both directions.
What are the strongest hinges?
If you’re looking for door hinges for a heavy or frequently used door, mortise hinges make a stronger and more reliable choice. Mortise hinges are more popular among exterior doors, as are mortise locks.
What does flapping mean on a helicopter rotor?
Flapping is the vertical movement of a blade up or down to increase or decrease lift in order to compensate for dissymmetry of lift. To equalize lift across the rotor disc, the advancing blade flaps up and the retreating blade flaps down. Flapping modifies the resultant relative wind by moving with or against the induced flow,…
How is the flapping of a blade related to feathering?
The place where the control rods connect to the blade, and the position of the flapping axis (for example, the position of the flapping hinge), both influence feathering and, therefore, blade angle. Take a look at the figure below. In this example, when a blade flaps up the blade angle will be reduced and vice versa.
Which is a side effect of increasing feathering?
Increasing feathering / pitch generally increases the aerodynamic forces on the blades, which changes the flapping. Unless the rotor and blade are infinitely rigid, which would cause other problems, flapping will be a (often useful) side effect of feathering.
Why do the blades move up and down on a helicopter?
The light blue arrows point to the two coning hinges. These hinges allow each blade to move up and down independently of the other blade. This would normally happen during coning, when each blade moves up until centrifugal force balances lift.