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31 Cards in this Set
- Front
- Back
What produces the lift required for helicopter flight?
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Rotor blades.
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When the camber is the same on both surfaces of an airfoil and results in a fixed center of pressure, what term describes the helicopter airfoil?
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It is symmetrical.
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What determines the amount of lift generated by a helicopter’s rotor?
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The lift of a rotor is proportional to the square of the length of the rotor blades.
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What is the result of highly polished rotor blades?
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Parasite drag is reduced.
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Where is density altitude at its greatest?
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At sea level.
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On a single main rotor helicopter, the tail rotor is used to counteract what force?
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Torque.
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Other than horizontal flight, how is rotor blade dissymmetry created?
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By the wind when the helicopter is hovering.
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What type of main rotor allows individual rotor blades to move in both a vertical and horizontal plane to reduce vibration caused by blade flapping?
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Articulated rotor.
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The upward bending of rotor blades is known by what term?
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Coning.
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When a helicopter is close to the ground, will it require more or less power to maintain a hover?
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Less.
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What term refers to main rotor rotation caused by air passing through the main rotor blades instead of being powered by the engine?
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Autorotation.
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What term describes the effect that occurs when a helicopter experiences an uncontrollable loss of altitude because of a combination of heavy gross weight, poor density conditions, and low forward speed?
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Power settling.
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What is the most common type of helicopter?
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Single main rotor with vertical or near vertical tail rotor.
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The CH-46 multirotor helicopter has what type of rotor design?
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Tandem rotor system.
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What feature provides the single rotor configuration with excellent directional control?
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The vertical tail rotor.
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In what direction does a tandem rotor operate that results in little torque?
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Tandem rotors operate in opposite directions.
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What pitch control system provides lateral helicopter movement?
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Cyclic pitch control system.
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What pitch control system provides vertical helicopter movement?
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Collective pitch control system.
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What does the rotary rudder system control?
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Directional heading.
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On the rotary rudder control system, what component is preloaded to 600 pounds and considered hazardous to personnel?
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The negative force gradient spring.
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How many separate banks of servomechanisms make up the auxiliary servo cylinder?
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Four (4).
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What component controls and transfers independent movements of the lateral, forward, aft, and directional controls?
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Mixing unit.
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The movement of what valve allows hydraulic fluid flow in the three primary servo cylinders?
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Pilot valve.
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What unit sends movement, through the adjustable pitch control rods, to the sleeve and spindle assembly of the rotary blades to change the angle of incidence of the blades?
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The swashplate assembly.
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What test is required after a helicopter has been rigged?
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A flight test.
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Proper blade tracking prevents what condition?
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Vibrations.
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What blade-tracking device can be used in flight or on the ground?
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The Strobes blade tracker.
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What assembly is comparable to a single disc wheel brake in its design and operation?
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A rotor brake assembly.
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What component prevents hydraulic pressure from entering the blade fold system during flight?
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Safety valve.
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What is the blade fold accumulator nitrogen preload pressure that maintains hydraulic pressure in the rotary-wing head?
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1,500-psi nitrogen pressure.
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Before you charge the blade fold accumulator with nitrogen, the blades should be in what position?
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Spread position.
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