Helicopters Flashcards

1
Q

When banking the helicopter, vertical lift is directed into

A

horizontal movement,

bank of 25 degrees requires 10% increase in lift

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2
Q

thrust is primarily created by

A

converting lift alterations of the pitch angle and AOA

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3
Q

profile drag

A

drag created by the frictional resistance of spinning airfoils,
allows drag to increase as velocity increases
remains midway, not dominating nor negligible

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4
Q

parasitic drag

A

caused by the non lifting portions of the helicopter, weight of the helicopter and its equipment, most dominant type of drag and increases with airspeed

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5
Q

induced drag

A

byproduct of lift created by rotor, only drag that decreases as airspeed increases, primary force at low speeds but meaningless at high speeds

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6
Q

a helicopter can adjust to more weight on one side by

A

adjusting the angle of the rotor disk to stabilize

but will cost lift, reducing performance

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7
Q

front loaded center of gravity

A

identified by fuselage tipping forward
cases helo to pull forward when hovering making slowing down and forward movements difficult.
result of having a heavy pilot in front, little cargo at rear
solution: add weight to back of helo

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8
Q

Aft loaded Center of Gravity

A

identified by fuselage tipping backwards

cause the helo to pull backwards when in neutral hover, and make accelerating more difficult

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9
Q

Primary flight controls in a helicopter

A

Collective, throttle, cyclic, antitorque pedals

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10
Q

collective pitch control

A

used to create lift and control vertical movement

succeeds by altering the pitch of the rotor blades. increased pitch = lift

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11
Q

throttle

A

control power to the engine

used whenever the RPM drops or rises beyond value. clockwise turn increases Rpm

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12
Q

correlator

A

links the collective to the throttle, automatically increasing or decreasing the throttle as the collective is used

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13
Q

governor

A

electronic sensor that tracks the current RPM directly. it will automatically adjust the throttle as needed if the RPM is out of desired range.
with this, touching the throttle is rarely needed

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14
Q

Cyclic pitch control

A

used to generate thrust and control horizontal movement,

functions by altering pitch of the rotor blades

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15
Q

Anti-torque pedals

A

controls pitch of the tail rotor blades
purpose is to counteract the torque of the main rotor, and increase or decrease past it
a pilot can control rotation for a new heading

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16
Q

trim control

A

used to level an aircraft in pitch and roll while eliminating yaw.

17
Q

four basic fundamentals or maneuvers

A

straight-and-level flight

turns, climbs and descents

18
Q

Straight and level flight

A

minimal control needed to keep moving, most efforts will be directed in keep helo level

19
Q

turns

A

if helo is flying at low speeds - performed by anti torque pedals
at high speeds- cyclic is used to bank the helo

20
Q

climbs and descents

A

collective is used to to climb or descent altering the pitch of the main rotor blades

21
Q

Hovering

A

Goal is to remain a set distance off the ground
collective acts as position control
anti-torque pedals are a rate control
cyclic: acceleration control

22
Q

Vertical takeoff to hover

A

start from a landed position to a hovering position

collective should be increased smoothly while maintaining the heading

23
Q

hovering turn

A

change the heading of the help while maintaining a constant position relative to the ground
anti torque pedals are primary controls for this

24
Q

Banking turns

A

goal is to change heading

cyclic is used

25
Q

normal climb and descent

A

primarily use collective and throttle

26
Q

Taxiing

A

primarily used to move in short distances

27
Q

hover taxing

A

employs hovering, forward flight, and hovering turns to move about
no more than 25 feet above ground
most often used for re positioning

28
Q

air taxiing

A

involves higher speeds and altitudes no more than 100 feet.
straight and level flight and banking turns are used
takeoff required for air taxiing and expected to avoid flying over vehicles or personnel

29
Q

Surface taxiing

A

kept on the ground the entire time
collective is raised until the helo is light on its wheels and also to move forward.
never should be move faster than a brisk walk

30
Q

Centrifugal force

A

causes rotating bodies to move away from the center of rotation

31
Q

centripetal force

A

force that keeps an object a certain distance from the center of rotation

32
Q

Gyroscopic Precession

A

when the applied force to a rotating object is shown 90 degree later than where the force was applied

33
Q

DisSymmetry of Lift

A

difference in lift between the advancing and retreating blades of a rotor systen

34
Q

effective translational lift

A

improved efficiency from directional flight, gained when helo moves forward
typically occurs between 16 and 24 knots

35
Q

transverse flow effect

A

difference in airflow between the forward and aft portions of the roror disk.

36
Q

Coriolis Effect

A

Objects in the Northern Hemisphere are deflected to the right, while objects in the Southern Hemisphere are deflected to the left. The coriolis effect thus tries to force winds to shift towards the right or left.