Helicopters

What operates a priority valve?. Hydraulic Pressure. Electrically. Mechanic linkage. Mechanical and electrically operated.

What does a hydraulic pump do?. Moves fluid. Creates pressure. Creates back pressure. Creates suction.

What dual type of instruments are used together by the pilot?. Rotor RPM and Engine RPM. N1 and N2. Engine RPM and Transmission RPM. EGT and ITT.

In a vertical steady-state ascent, the helicopter has to overcome?. Thrust and lift vs weight and drag. Lift and weight vs drag and thrust. Torque and thrust vs lift and drag. Thrust and weight vs lift and drag.

The amount of coning is dependent on?. Lift and Weight. Weight and Thrust. Lift and Drag. Weight and speed.

Torque is based on which law?. Newton’s third law. Newton’s first law. Newton’s second law. Newton’s fourth law.

Which rotor head design has a inability to correct for dissymmetry in lift?. Rigid. Semi-rigid. Fully-articulated. Semi-articulated.

Which rotor head design compensates for the Coriolis effect?. Semi-rigid. Rigid. Semi-articulated. Fully-articulated.

Which rotor head design uses individual flapping hinge for each blade?. Fully-articulated. Semi-rigid. Semi-articulated. Rigid.

What head design relieves bending forces at the root of the blade and allows coning of the rotor?. Fully-articulated. Semi-articulated. Rigid. Semi-rigid.

What force is imposed on a helicopter in forward steady state flight?. Translational lift. Dissymmetry of lift. Transitional lift. Gyroscopic precession.

At what speed does effective translational lift take place?. 15-20 mph. 10-15 mph. 5-10 mph. 25-35 mph.

During autorotation, the flow of air through the main rotor is?. Upward. Non-existent. Downward. Not effecting the rotor blades significantly.

Which rotor head system has ground resonance problems?. Fully-articulated. Semi-rigid. Semi-articulated. Rigid.

A European made helicopter in forward cruise requires?. Right pedal. Left pedal. Neutral pedal. Full right pedal.

A U.S. made helicopter during take-off requires what anti-torque input?. Left pedal. Right pedal. Neutral pedal. Negative pitch.

During autorotation the tail rotor must?. Supply negative thrust. Supply positive thrust. Be neutral. Be strong enough to absorb landing shock.

What causes the tilt of the tip-path plane of the main rotor?. Cyclic control. Translating tendency. Flapping hinge. Collective pitch.

A movable stabilizer is moved by?. The cyclic. The collective. Hydraulics. Pneumatics.

What type of bearings are used on control linkages?. Spherical bearings. Ball bearings. Needle bearings. Roller bearings.

On metal rotor blades, the skin is?. Simply a wrap-around, giving the blade its aerodynamic shape. Bonded to the spar. Used as an abrasion shield to the blade. The main structural component.

Blade alignment is?. Necessary on fully-articulated heads. Spanwise balance. Chordwise balance. Not required on semi-articulated heads.

A main rotor is out of track, the vibration is?. 1:1. 1:2. 1:3. Lateral.

A helicopter is in forward flight; the mast is under?. Torsional and tension load. Radial and torsional load. Torsional load. Tension.

What type of rotor is susceptible to mast bumping?. Semi-rigid. Semi-articulated. Rigid. Fully-articulated.

The drive link on a swashplate is connected to?. The mast. The cyclic. The counter weight fly bar. The mixer box.

A helicopter is overstable and control response is delayed; the problem is likely?. To soft stabilizer dampener. To hard stabilizer dampener. Out of rig rotor. Out of round rotor head.

On a helicopter having a free turbine engine, the twist grip is used to control what?. Compressor RPM. Power turbine RPM. Max. beep. Throttle.

Artificial “feel” is accomplished by what?. Gradient unit. Magnetic brake unit. Control boosts. Hydraulic dampeners.

Hydraulic pumps are of what type?. Gear. Piston. Gerotor. Vane.

What would happen if the freewheel unit seized during a autorotation?. The rotor would drive the engine. The engine would drive the rotor. The rotor would drive the transmission. Allow the engine to drive the transmission.

A helicopter transmission uses?. its own lubricant. Engine oil. An oil/fuel mixture. Hydraulic oil and back pressure from the engine.

Tail rotors may be dynamically balanced with the?. Chadwick-Helmuth. Strobex. Vibrex. Phazor.

What type of airfoil is the horizontal stabilizer?. Inverted Dissymmetrical. Symmetrical. Inverted Symmetrical. Unsymmetrical.

What does an inverter do?. Converts DC to AC. Converts AC to DC. Changes field direction. Maintains a constant AC voltage.

What type of fuel system is used in helicopters?. Force feed. Gravity feed. Suction feed. Back Pressure.

A movable horizontal stabilizer is used for?. Decrease fore and aft cyclic movement. Increase stability and move the C of G further aft. Increase stability and move the C of G forward. Increase fore and aft cyclic movement.

An ILS system is comprised of?. Localizer, Glideslope, Marker beacons. Localizer, Glideslope, VHF radio. Localizer, Glideslope, UHF radio. Localizer, Glideslope, Inner marker.

What part of the ILS system guides the aircraft to the center of the runway?. Localizer. Marker beacon. VOR beacon. Glideslope.

The VSI is connected to what system?. Static system. Pitot system. Pitot/static system. Central pressure standpipe.

Conical elastomeric bearings used in a rotor head provide?. Absorption of high radial and axial loads with some movement in both directions. Movement about three axes and absorb heavy torsional loads. Absorption of low radial and axial loads with very little movement in any direction. Movement about two axes and absorb light torsional loads.

In a turbine powered helicopter, the rotor brake system operates on?. Independent hydraulic system. Manual operation. Transmission oil. Engine oil.

The relationship between blade alignment is necessary for the specific purpose of placing the blades C of G with?. The hub of the rotor. C of P. Chordwise balance. The longitudinal axis of the helicopter.

An Underslung rotor is utilized to counter?. Coriolis effect. Dissymmetry of lift. Gyroscopic precession. Cyclic drift.

What property puts the action at a different point on the swashplate?. Gyroscopic precession. Dissymmetry of lift. Collective pitch. The cyclic control.

In forward steady flight, directional change is affected by what?. Rotor disk tilt. Collective pitch change. Negative tail rotor input. Positive tail rotor input.

A helicopter in forward flight changes course by: Tilting the main rotor disk in the desired direction. Varying the pitch of the main rotor blades. Tilting the tail rotor disk. Varying the pitch of the tail rotor blades.

The vertical flight of a helicopter is controlled by: Increasing or decreasing collective pitch. Increasing or decreasing both cyclic and collective pitch. Increasing or decreasing cyclic pitch. Tilting the rotor disk.

A variation of the blade pitch as the blades rotate through the tip-path plane is controlled by: The cyclic pitch control. The collective pitch control. Raising the advancing blade. Lowering the advancing blade.

A rotor system having hinges at the root of each blades, which permits the blade to move up and down is known as: An articulated rotor. A semirigid rotor. A rigid rotor. A semiarticulated rotor.

A semirigid rotor is underslung in order to: Increase stability. Decrease stability. Decrease rigidity. Increase rigidity.

During a vertical flight at a steady rate: The sum of lift and thrust is greater than the sum of weight and drag. The sum of lift and weight is equal to the sum of thrust and drag. The sum of lift and thrust is equal to the sum of weight and drag. The sum of lift and weight is greater than the sum of thrust and drag.

A condition which is caused by the difference in airspeed between the advancing and retreating rotor blades is: Dissymmetry of lift. Coriolis effect. Gyroscopic precession. Translational lift.

Some types of rotor are permitted to flap to compensate for: Dissymmetry of lift. Coriolis effect. Centrifugal force. Blade tip overspeed.

Greater downwash effect through the aft part of the main rotor disk compared to the forward part of the disk is known as: Translational lift. Transverse flow lift. Transitional lift. Ground effect.

If a single-rotor helicopter is in horizontal flight, the angle of attack of the advancing blade is: Less than the retreating blade. More than the retreating blade. Equal to the retreating blade. The same at all points around the rotor disk.

The magnitude of the coning angle is determined by the relationship between the centrifugal force and: The lift produced by the blades. Size of the tip path plane. The angle of attack of the blades. The axis of rotation of the rotor system.

Cyclic control inputs to the swashplate are not located at the point where the action is to occur, because: Of gyroscopic precession. Of swashplate rotation. Of probable damage to the drive links. This would prevent tilting of the swashplate.

The torque developed by the main rotor is an example of: Newton's third law. Newton's second law. Newton's first law. Newton's fourth law.

Coriolis effect is associated with: Changes in the speed of rotation. Gyroscopic precession. The rising of the advancing blade. The change in the coning angle.

Ground resonance is a problem associated with: Fully articulated rotors/articulated rotors. Semirigid rotors. Rigid rotors. Non-articulated rotors.

During autorotation, the flow of air through the main rotor is: Upward. Downward. Same as normal powered flight. Dependent on the position of the cyclic stick.

During autorotation, on a conventional American designed helicopter, the tail rotor will be: At a negative pitch. At a positive pitch. At a neutral pitch. The same as normal flight.

To counteract torque during takeoff, conventional European-made helicopters require: Right pedal to be added. Left pedal to be added. The pedals to be held in the neutral position. Left pedal to be added and maximum beep applied.

Translational lift is noticeable at around: 15 to 20 mph. 3 to 5 mph. 10 to 12 mph. 25 to 45 mph.

Horizontal stabilizers are shaped as: Inverted unsymmetrical airfoils. Inverted symmetrical airfoils. Unsymmetrical airfoils. Symmetrical airfoils.

Pitch link rod ends are usually fitted with: Spherical bearings. Plain bearings. Sealed bearings. Elastomeric bearings.

The conical elastomeric bearings used in rotor systems are capable of: Absorbing high axial and radial loads with some movement in both directions. Absorbing low axial and radial loads, and absorbing heavy torsional loads. Absorbing high radial loads and providing movement in radial oscillation. Providing movement about the three axes and absorbing heavy torsional loads.

In a hydraulic system, the purpose of the pump is to: Move the fluid. Relieve pressure. Generate pressure. Regulate pressure.

Hydraulic pumps used for high pressure output are normally: The piston type. The gerotor type. The gear type. The vane type.

In a hydraulic system, priority valves are: Both electrically and hydraulically actuated. Mechanically actuated. Hydraulically actuated. Electrically actuated.

The variation in the angle of incidence of a blade between the root and the tip is: The twist angle. The chord angle. The span angle. The feathering angle.

The skin on metal rotor blades: Is simply a wrap-around giving the blade its aerodynamic shape. Is the main structural component of the blade. Acts as an abrasion shield to the blade. Is bonded to the spar only.

Blade alignment establishes the correct relationship of the blade center of gravity to: The chordwise balance. The center of pressure. The spanwise balance. The main spar.

Rotor blade tracking is carried out to ensure that all blade tips: Follow the same tip path throughout the cycle of rotation. Increase their angle of attack by the same degree when the collective is raised. Have the same angle of incidence. Have the same angle of attack.

The vibration usually associated with track is: 1:1 lateral vibration. 1:1 vertical vibration. 2:1 lateral vibration. 3:1 vertical vibration.

If the amplitude of a vibration remains constant throughout the rpm range, the rotor is: Out of chordwise balance. Out of spanwise balance. Out of track. Serviceable.

One bad damper, on a fully articulated head, would result in: 2:1 lateral vibration. 1:1 beat or scuffle. 2:1 vertical vibration. In both an out of track and balance condition.

In flight, the main rotor mast usually absorbs: Both torsion and tension loads. Both torsion and radial loads. Torsion loads. Tension loads.

Damage due to mast bumping is associated with: Semi rigid rotor systems. Rigid rotor systems. Semi articulated rotor systems. Fully articulated rotor systems.

On most helicopters, the rotating part of the swashplate is driven by a drive link attached to: The mast. The cyclic inputs. The collective inputs. The main transmission.

The collective twist grip on free turbine helicopters is used to control: The compressor rpm. The turbine rpm. The beep rpm. The rate of descent during engine failure.

Moveable horizontal stabilizers are used to: Increase controllability and lengthen the C. of G. range. Decrease rigidity and shorten C. of G. range. Decrease fore and aft cyclic control. Increase lateral cyclic control.

An overstable helicopter and delayed control response could be the result of: Soft stabilizer bar dampers. Hard drag hinge dampers. Hard stabilizer bar dampers. Improperly adjusted collective control.

During autorotation, seizing of the free wheeling unit would: Allow the rotor to drive the engine. Allow the engine to drive the rotor. Allow the transmission to drive the rotor. Have no effect.

On a turbine powered helicopter, the pressure required to operate the rotor brake is normally provided by: A dedicated hydraulic system. Transmission oil pressure. Engine oil pressure. Engine bleed air.

On helicopters using hydraulic boosting of the flight controls, artificial feel is usually provided by: A gradient unit. A magnetic brake. A centrifugal brake. An irreversible valve.

Which statement is correct concerning "torque effect" on helicopters?. Torque direction is opposite to rotor blade rotation. Torque direction is the same as rotor blade direction. As horsepower decreases, torque increases. As horsepower increases, torque decreases.

Most helicopter fuel systems are: Forced feed systems. Free flow systems. Gravity feed systems. Suction feed systems.

The dual tachometer indicates: Engine and main rotor rpm. Engine and tail rotor rpm. Engine and transmission rpm. Compressor rpm and free turbine rpm.

Dynamic balancing of the tail rotor may be accomplished with: The Chadwick-Helmut Vibrex System. The Phasor only. Both Phasor and the Vibrex. Both the Phasor and the Strobex.