Mod 4-5 Quiz Flashcards
what is induced flow
the direction of airflow through the rotor blades.
what is translational lift? what effect will it have on the aircraft?
transitional state that a helicopter experiences moving from a hover to directional flight
will cause buffeting of the airframe
when a helicopter is in a hover, what is the difference between being in ground effect (IGE) and out of ground effect (OGE)
IGE - the helicopter is hovering one half to one full rotor disc diameter from the ground causing the downwash from the rotor blades to create a cushion of air that allows the helicopter to use less HP while Hovering
OGE - the helicopter is one half to one full rotor disc diameter away from the ground so downwash has no effect on the required power for a hover.
True or False, a helicopter can hover at a higher altitude while in ground effect that it can out of ground effect
true
what is dissymmetry of lift? what is its effects of the aircraft?
a difference in blade speeds while the helicopter is in directional travel
can cause heli to flip
what are two solutions for dissymmetry of lift
Flapping hinge and Differential cyclic
what is differential cyclic
a difference in blade pitch dependent on the position of the blade
retreating blades will have higher pitch while advancing blades have lower pitch
what is the law of conservation of angular momentum?
the theory that when the centre of mass of a rotating object moves towards the centre of rotation, the object will accelerate
what are two solutions to the conservation of angular momentum problem
lead lag hinge
underslung mounting
what is a retreating blade stall
it is when the rotational velocity and the velocity of flight are equal causing that blade to stall while the other blades continue making lift
what is vortex ring state
decent through the rotor downwash causing the helicopter to eat its own wake and stall the blades
what is mast bumping
the action of the rotor head striking the mast as a result of low G pushovers
what is a major consequence of mast bumping
separation of the rotor head from the airframe
what movement do anti torque pedals control? how do they control it
yaw
changing the pitch of the tail rotor blades
what is the collective? where is it located
the control used for throttle adjustments
located to the left hand side of the pilot seat
what additional controls can be located on the collective
landing lights
start switch
idle release
what is the cyclic? what movement does it controll
the cyclic is the main joystick located between the pilots legs. it is used to control the pitch and roll movements of the aircraft
what additional controls can be located on the cyclic
push - to - talk
cargo hook release
trim
what does a mixing unit do
converts separate cyclic and collective inputs into a common set of outputs
what is the difference between a scissor link and a drive link
scissor link is connected to the stationary swashplate while the drive link is connected to the rotating swashplate and the mast and provides rotational force
what effect does centrifugal twisting force have on a rotor blade
wants to return the blade to low / fine pitch angle
what is used to counteract centrifugal twisting force
collective spring or counterweights
what is flight control friction
it adds extra friction to a flight control to hold it in a set position and take the load away from the pilot
what is aerodynamic twisting force
it wants to move the rotor blades to a higher pitch angle
what is artificial feel used for
it provides haptic feeback to the pilot to allow them greater control of the aircraft
